After making the decision to use cJSon, I set about getting the bare minimum together to see the output. I incorporated the c and h files into my project, and by following the example on the git hub page ( I created my first JSon string.

Over the years, I have implemented several protocols to transfer data between clients and servers, both in the traditional network socket sense as well as for various projects that use serial ports. This usually comes down to throwing various ideas around and eventually settling on a "colon deliminated line" where each instruction or status report is a single line, with each element separated by a colon. While this is a simple on-wire protocol, it does require the parsing side to know how many colons to expect, as well as error handling for when there are an unexpected number of colons.

As mentioned sometime ago, now SolarDock is essentially finished, I have reopened my PSU project.

I shook the collected dust off the PCB and source code, and started looking into what was outstanding. Fortunatly I had been pretty thorough with the ticketing system built into my instance of gitlab-ce so this didn't take too long.

I confirmed that the serial port stuff worked, and set about getting the LCD character display to work. Here started the problems.

With another month of nearly flawless behaviour, I am going to have to say that SolarDock is done.

Sure there is some weirdness when turning on and off where some postcaps don't "hear" the NRF and so don't turn on or off in response to the broadcast message. This appears to be fairly random and clears up on it's own without any intervention from me.

Last weekend, we sat out on the dock for a couple of hours one evening with all of the lights on, and it worked without issue, the only effect was that it took a little longer to reach full charge the following day.

This weekend I happened to be on the dock around the time that the sun was most on axis. I took a look at the charge controller and saw this...

I have also been running the lights until 0100 each night which is around 5 hours at this time of year. The battery voltage has been over 12.5v for the entire week, including the night after a poor charging (cloudy) day on two separate occasions. I have yet to see how it behaves with several consecutive days of poor charging, but I am confident it'll be OK

Back on November 6 I wrote that I was seeing 1.1A coming from the panel. This weekend I was out on the dock in the morning and I looked at the charge controller, the panel was at the time producing 4A!

This was not at peak production time so I think the peak is even higher, I may never know as I don't have the time to site and watch it. I think at some point hook I may up my serial DVM and record the output against time. I can use the panel fuse holder for this.

About a week ago I decided that before I installed the tracker and really invested time into it, I would try a couple of ideas. This involved two related items, more battery capacity and swapping out the repaired panel for the never broken one.

After trying to cut the micro controller off the board and in the process lifting pads, I needed to populate a new board. I was fortunate enough to be able to rescue everything but the micro. I haven't yet tested the ADC sections, but I am hopeful that they and the opto-isolator are still good.

Soon after my last post at a routine eye exam, they found a minor issue, however it has meant that I have needed eye drops in the interim. Soldering small SMD packages with one eye dilated was challenging.

I got past that, and have been working the tracker firmware. Initially the device would not program, I think this is due to the opamp output holding the pin at the wrong level, I solved the issue by lifting the opamp pins in question.I don't know if this has broken the board by lifting the pads too, but it does now program consistently.

As I mentioned in the previous post, I was going to design and build a solar tracker. As time has gone by, this has become more necessary.

When I first set the panel angle I was getting great performance (fairly consistent 1.1A off the panel). Now, 3 weeks later, not so much as the angles are all wrong again, and I am back to getting about 20 minutes of runtime in the evening.


Subscribe to RSS - blogs