Solar Shed Update

 

A quick update on the Solar Shed progress.  The snow has melted and there is some sun.  I have not been formerly taking down readings, but in general the battery has charged to slight over 14VDC on it at the day and about 13.8VDC in the morning.  Which is comparable to what I saw on the bench.

Moving to the real world is always going to bring on new issues.  What problems did I have, well 😛

• For the switch that turns on the LED Lighting, for some reason the weak pullups on that input was off.  The overhead LED  lights would go on and off randomly.  I was never a fan of those weak pullups, not sure why I did not just put a 10K or 100K pullup there.  Space and cost were not a driving factor.
• Next this switch does not wake up the PIC.  When is the PIC sleeping, at night .  When do I need the light, at night.  It is a simple fix, but I am waiting to gather more changes before fixing this.
  
• I had added a relay for selecting power source for PIC and etc, from either the battery or the solar panel.  I implemented the logic to use the Solar Panel as the power source whenever it is above about 8VDC.  But forgot to change the TRIS register for the drivers to an output.  No wonder I could not drive the relay to change the source.  Now as long as there is sufficient solar panel voltage, that powers the PIC and etc.
  
• All of the conversion constants moved a little, again.  1% resistors are nice, but they are still only 1% accurate.  Another change is to add an OLED screen that shows the ADC count instead of a calculated voltage.  Maybe that will help refine the conversion chart I showed earlier.
  
• The 7.5F supper cap took over 2 mins to charge the first time.  I thought there was a short somewhere since the voltage would not rise.  Then I remembered that an uncharged cap is a short. 

I have been thinking of a good test for the super cap.  What I am thinking now is around 8PM disconnect the battery.  The sun will be down, so no solar power.  Then before the sun lights up the solar panel, check if the PIC is still in sleep mode.  One way is to press one of the buttons that will illuminate on the LEDs.  It is a left over debug routine, that is actually quite useful.  The other is to measure the voltage at the Suoer Cap and see if it is providing sufficient voltage.  Then this test needs to be repeated without the OLED installed.  

The process continues.

 

Building Common Libraries

Brick Controller 2

Brick Controller 3

 Light Buddy 1

Light Buddy 2

 I am up to four devices now that have some form of common LED lighting.  Two of which have motor controllers, the basic PWM interface.  As I keep developing new LED lighting effects, going back to each one of these devices and making the changes is getting too time consuming.  Not to mention that I am not getting consistent effects.  

Earlier I started on a quest to make a common library of firmware that can be updated and then automatically apply across all the device platforms.  After a few days of work and frustration 😎, I have achieved success.  Though there is still some testing to be done, but the basics work.  Here is a short description of how I got there.

The two LED controllers I am using right now are LP5569 and LP55231.  I use these because they are mostly firmware compatible with each other.  Though one is a low side driver and the other is a high side driver.  When I am not using these LED controllers, I use the built in PWM controllers in the PIC processors.  Finally when the LED is very basic, either off or on, then the control is the generic IO control of the PIC processor.  Regardless of the driving source, my hardware designs abstract the source away and present a consistent hardware interface of a low side driver.  

Both the LP5569 and LP5231 have I2C interfaces.  These were the only devices in any of these designs that had an I2C interface, thus the I2C driver was intertwined in the LP55xx code. The first step was to extract the I2C driver code and make it a standalone module.  While this was not difficult, it take some time to "unwind" all the code.  Now I can add other I2C devices, without having to include I2C driver code. 

Next was to unwrap the the LED effect (STYLE + FEATURE) from the driving source (LP55xx or PIC).  This meant creating two different modules, one for the LP55xx and one for generating the LED effect.  As has been described in previous posts, the LED effects reduces to a PWM value in either the controller or the PIC processor.  Thus the module I call PWMCtrl, generates this single PWM value for any 100ms time slice.  Then if a LP55xx is the destination, the value is passed to that module for writing into the LP55xx IC.  (Actually because of the way these ICs are set up, all nine channels are updated in a single transfer.  Thus I wait until all the LP55xx LED channels have their PWM values updated before transferring data.)  If the destination is the PIC processor, then it is a simple register update.

The final change was actually splitting the PWMCtrl module into a common section and a local section.  The local section contains all of the device initialization, the cooperative task function and any hardware dependence.  The common section is mostly the LED effects generator.  This code computes the PWM value needed. Thus I now have one place where all effects are calculated, which provides consistent looking effects.  I have not looked very carefully at this split.  There probably is a way to combine these through some MACRO definitions.  But that will be for later.....

Light Buddy 2 Functionality

Light Buddy 2

When I built LB2, I developed some unique LED features as explained in an earlier post.  This image shows the current setup of the Windows APP.

 LB2 was originally setup as four pulsing LEDs and two "conventional" LEDs.  LED_A thru LED_D would have one of the following LED Styles

• OFF
• STEADY
• PWM1
• PWM2

Not sure if the difference between PWM1 and PWM2 will be more than different timing.

LEDs LED_1 and LED_2 being "conventional" would have the following LED Styles

• OFF
• STEADY
• BURST
• CYCLE

What you can do is add features to these LED Styles.  

STEADY - allows you to add the features SAWTOOTH and TRIANGLE.  The other two do not make much sense, the LED is always on.

BURST - allows you to add the ALWAYS ON and REPEAT ON.  In the future TRIANGLE might be added.

CYCLE - allows for all four.  The red LED on the top of dome in this video, is CYCLE STYLE with a TRIANGLE/ALWAYS ON as the selected FEATURES.  One use for this a heartbeat type effect.  A definition of the different STYLES and FEATURES can be found in this post.

I have other ideas for LED Lighting effects, just need the time to work them out.

 

 

LED Styles and Features

 This is a video I posted earlier about the functionality of Light Buddy 2 in this compact generator detail.

 

In the process of building and programming LB2, I further developed the concept of different LED styles.  In the end, it is all about turning the LED on/off and how long it is on and how long it is off.  In this process I have come up with attributes that I call LED Styles and LED Features, for lack of any better words.  Along with these Styles and Features, there is a PWM parameter that effects the brightness of the LED.  When the PWM parameter can be applied is a function of the particular controller.

LED Styles

There are ten LED Styles as described here.

• OFF - the LED is off.
• STEADY - the LED is on. Brightness may vary by using the PWM parameter.
• BURST1 - the LED does a quick burst of LED on/off.  The intensity can vary with the PWM parameter.  This simulates a Laser weapon.
• CYCLE1 - the LED cycles on and off in equal on and off periods.  Brightness may vary by using the PWM parameter.
• PWM1 - the LED is varies in intensity as does the on and off period.  All three LED attributes are randomly varied, intensity, on time and off time.  The PWM parameter has no effect.  This simulates an arc generator or Tesla effect.
  
• BURST2 - same as BURST1, just different timing.
  
• CYCLE2 - same as CYCLE1, just different timing.
  
• PWM2 - same as PWM1, just different timing.
• Program - future style.  Some type of user programmability.
• ON/OFF -  future style.

LED Features

There are four LED Features as described here.

• Sawtooth - the LED will increase (slowly, though this is a relative term) in intensity.  When it reaches maximum intensity, it goes back to OFF immediately.  The PWM parameter has no effect.
• Triangle - the LED will increase (slowly, though this is a relative term) in intensity.  When it reaches maximum intensity, it then will decrease in intensity until it reaches the minimum intensity.  The PWM parameter has no effect.
  
• Repeat - when applied to a feature, the feature will repeat at some interval, with an off gap in between.
  
• Always ON - when applied to a feature, the feature will repeat at the minimum interval.  For Sawtooth and Triangle the next cycle will start immediately.
  

 The features were all possible in the script language.  Though they would be cumbersome to implement especially at the fine detail the direct implementation is done at.

 

Solar Shed - Assembled

It is mostly assembled now.  First step is test the ADC inputs and make sure they are working correctly.  I built this spreadsheet.  

• Column A is Vcc=3.29VDC and ADC size is 1024 counts
• Column B is Battery input voltage
• Column C is Battery voltage at the ADC input
• Column D is the ADC counts for that voltage
• Column E is LT1085 voltage at the ADC input (input voltage is from column B)
• Column F is the ADC counts for that voltage
• Column H is Solar Panel input voltage
• Column I is Solar Panel voltage at the ADC input
• Column J is the ADC counts for that voltage

Finally the three numbers in row 2 (0.2015, 0.2035 and 0.1286) are actual measured voltage ratios of the voltage input and what is present at the ADC input for each input. Even though I used 1% resistors, there is still +/-1% over the marked resistor values.  And to be fully transparent, even though there are unity gain low bandwidth (10KHz) OP-AMPs driving the PIC ADC, the layout probably could have been better.  It is as tight as SMT0805 resistors/capacitors would allow and is surrounded by ground plane.  But not being an Analog Guru, it is probably just OK.  Below the table You can see the layout for the three ADC inputs. (It;s late and my hand is not quite steady, s the picture is a little fuzzy)

 

Then I compared these numbers against what the ADC was reading.  Finally I tweaked the Vcc number a few millivolts to get  a more consistent match of the table values to the actual ADC readings.  During this process I noticed that I had left the weak pullups on the three ADC input pins on.  After turning them off, the readings were much more consistent.

The next issue was going in and out of sleep.  Just needed to make sure that everything I turned on/off before sleep, was turned off/on after coming out of sleep.  So at least on the desk it seems to work as before.  There are a few enhancements and more testing that are needed

• When the solar voltage is high enough, run the PIC from the solar panel.
• Install the super cap and test it.
• Maybe the PIC runs from the solar panel all the time and the battery only powers the LED lighting in the shed.

Ran the system in sleep all night.  Starting battery voltage at 10PM was 13.68VDC.  At 8AM the next morning the voltage was 13.51VDC.  Now in LiFePO battery system this doesnt mean much.  Unless you have a calibrated battery gas gauge IC connected, there is no way to know how much battery life was consumed.   We must remember that a LiFePO battery discharge curve is quite flat until the inflection point.  What is important is the current numbers from the previous post, the system with OLED and in SLEEP, consumed 2.25mA from the battery.  That should be equivalent to 18mA-Hr.  Fully charged (and new) the battery is rated at 9.6A-Hr.  So over night we used about 0.2% of the battery.  

I will be interested to see what the super cap does.  That will be the next test.  Still waiting for the sun to appear and the snow to melt.

 

Cliff Wall Interior Update 1

 

Here is a rendering of the interior of the Cliff Wall for the first floor.  There is still a smaller section above that is located on the same level as the gantry on the hangers.  Here is a closeup of the area around the minifigs.

What do you do with the smooth wall behind the Minifigs and along the sides.  Across the center I placed some brackets.  To those brackets I attached a 6x12 plate.  The upper four rows are covered in black tile.  On the black tile will be a sticker of a radar/computer screen.  The bottom two rows have a 1x6 tile of BLUE and LIME to match this color accent scheme of the entire MOC. That still leaves two 6 x 5 blank panels of wall space on each end.  More brackets with clips and hooks for tools is probably the answer.

One thing that is of concern, is that the Transparent Light Blue windows are locked in place.  There is no way to get behind them and reposition minifigs or other items that might fail.  This wall of glass has to be movable without taking the entire module apart.  Especially these with cliff wall structures on the other side.

I worked on this and here is what I hope is the solution.

 

The first two pictures show the concept from a long view.  Disregard the Brick pile surrounding the MOC, just some excess Bricks from building, tear down, building, tear down, etc. etc etc. The left side uses a 1x4 hinge plate at the top and the bottom.  I then built a pillar that secured the hinge plate in place.

 

This picture shows the large screen area in the back.  The pillar on the right is the latching mechanism.  

These two pictures show a closeup of the latching mechanism.  Positioning the clips was time consuming.  Plus I have never liked stacking 1x1 plates or bricks.  Keeping them straight is difficult.  The pillar required some work to get it stable.   

Using this as a base, I went back into Studio and updated the design without part restrictions.

This shows the two pillars for the moving window.

This shows the latching mechanism.  By using part 30241b

instead of 

we get a less of the 1x1 plate issue not lining up correctly.

Is this final?  Cannot answer that question right now.  What I do like is that this arrangement gives depth to the front of the model, which is always good. But at some point I need to start building out, the end of April if fast approaching.

Crazy Idea or Something Cool

 

Somehow I either bought or acquired these LEDs from somewhere.  They are RGB plus white.  Regardless of how I acquired them, they very similar in package to these.

I designed a similar PCB, 8mm x 16mm or equivalent to a 1 x2 plate/tile, which is what the picture at the top of this blog post is.

This LED can do RED, GREEN, BLUE, or WHITE or any combination thereof.  Now the downside to this is it will take up to four LED control lines to do this.  What I don't know yet is how bright these are.  Some of that can be compensated for with the individual resistors.  I suspect some experimentation will be needed to balance out the color intensity.

Here are three ideas so far.

1. In the Space Base that ability to switch between RED and WHITE (or WHITE and any RGB LED).  So a working space can be in WHITE light and then when activity is about to change, the LED will switch from WHITE to RED.  Now this can be done with two LEDs, but there is some convenience of having just one device installed.
2. Using random PWM signals to the RGB LEDs.  This might produce a much better Tesla Effect than just using a single white LED.  
3. Using RED and GREEN is some kind of stop and go scenario. 
   

As time goes by, I am sure I will think of other ideas.  While most scenarios can be done with multiple LEDs, the convenience of a single device is very strong. Also if all the LEDs are wired, then the designer will have ultimate flexibility.

 We will see what they can do a week or so.