Saturday, February 25, 2017

BBBC 2017 #25

This post is part of ToadMama's Brave, Bold, Blogger Challenge (BBBC) 2017 which is an attempt to make February go by a little more quickly. There are 28 topics, one for each day. 

Share the 25th image you come to on your camera or phone

Finally a kinda straightforward challenge. The phrase "you came to" adds some ambiguity but I'll go for the straightforward approach. Go back as far as the library goes and count forward by 25. Unfortunately, that gave me a photo that I didn't even take so I counted 25 of my photos. A sticker bush in Ethiopia is the 25th picture on the phone though it wasn't taken on the phone. In fact, I didn't even take the phone on the trip since I didn't want to deal with international roaming and AT&T.

BTW, this is the actual 25th photo on my phone. I had imported some photos for a friend from a photo CD. This is George Rahn at his shop with some visiting moto-tourists. He was well known in the BMW motorcycle community and was sought out by many traveling through the area.

Connecting to the Tristar

Not related to the challenge but I picked up a another serial to USB communications cable. "Another" is because I must have a half dozen of these lying around somewhere as I needed them to connect to network equipment over the years. The Tristar TS-45 charge controller has a DB9 serial port so I just had to see what I could do with it. There is a lot of discussion online but they are all dealing with the much more costly Tristar MPPT charge controller. I had difficulty even finding out what kind of serial cable was expected or if a null modem was needed. So I just plugged it in to see if it worked. It did.

Using the serial port requires some free software from the Morningstar website and, of course, it's Windows only. But I just happen to have a Windows 10 machine lying around. It is a convertible (laptop/tablet) but it did have a USB port. Once I installed the drivers for the USB/serial cable, I fired up the MSView software. It found the Tristar right away at Com4. I used it to check the status. This is really the only way to see if everything is working as there is no display on the Tristar. They do have an optional display but it almost doubles the price and one very good solar website said that it's a waste of money. Get a Trimetric monitor instead. The temperature sensor is registering +6°C, it shows the input voltage, the battery voltage, charge current, etc. All of these are "live" and if the computer was left connected, all of this data could be logged and graphically displayed. This is the feature that I was attracted to. There are some Raspberry Pi data logger projects on the Internet that collect and display the data. To me that sounds like something I'd find interesting.

An interesting number is the target voltage of 15.86 volts. This is the temperature compensated absorption voltage. The voltage target is set to 14.8 volts for flooded lead acid batteries at 25°C. Since the battery bank is 6°C, the absorption charge voltage is increased to compensate for the lower temperature. 


  1. Cool stuff what you can see using the serial connection and free software....I bet you can find a Rasperry Pi device to log the data for you somehow....or, mount a LED panel within the 5th Wheel so you can gaze at it anytime you want. :)

    1. And I just happen to have several Raspberry Pi 3 Model B just sitting on the shelf. I think one is just set up with Raspbian already on the SD card since I was going to set it up as an OpenVPN server. But the Pi 2 had more than enough CPU capacity for that. I found a forum where someone wrote a python script to poll the Tristar every 5 seconds. Then another script to graphically display the data. Apparently the challenge is finding a USB-Serial cable that works with Raspbian. Instead of a dedicated panel, I could simply have a web server on the Pi connected to the internal network. Then maybe another Pi inside with a touchscreen. Something to play with on the trip...

  2. I did the opposite, the 25th most recent photo. It has been interesting to see how each person interprets each challenge.