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Tag: Troubleshooting

Blab

We did it, boys

2020-07-14

Well it has been done.  110F has been broken bbb_hvac=> select * from data.home_data where attic_temp = (select max(attic_temp) as attic_max from data.home_data) order by time_stamp desc; row_id | time_stamp | ac_compressor | ahu_fan | ahu_heater | ahu_return_temp | ahu_supply_temp | attic_temp | space_1_rh | space_1_temp | outdoor_temp | outdoor_rh ———+—————————-+—————+———+————+—————–+—————–+————+————+————–+————–+———— 8725659 | 2020-07-12 17:09:10.715058 | t | t | f | 73.6723 | 57.9939 | 113.597 | 57.2703 | 71.1624 | 94.1 | 59.5273 Read more…

Blab, Blab, Hardware

Math + facts = suck

2020-07-09

In the last post I did some basic arithmetic to see if the system as designed should be able to measure 110F.  This post is about verifying the physical reality to see if matches the pristine mathematical theory. To turn the VICTD into temperature in Kelvin the function is below.  We know this from the previous post. $$T_K = V_{ICTD} \times 10^3 $$ Measuring the output of the probe I get a reading of 0.30111V.  Read more…

Blab, Hardware, Software, The Home Automation System

2018-09-03

2018-09-03

I know I’ve said it before, but I will go ahead and say it again: the end is in sight.  In the last few days I’ve addressed the last few remaining issues: 1. Persistent offset on analog input #8 (ICD4) Turned out to be an input voltage offset issue.  See here for more details. 2. ADC input weirdness on analog inputs 4-8 (ICD inputs) The short version is that the op amp output is at Read more…

Hardware, The Home Automation System

2018-08-30

2018-09-01

One of the current and hopefully last hardware niggles is the unexpected value on the last analog input.  It’s consistently reading millivolts higher than the other analog inputs.  This has been verified with and without a device attached to it. The analog input in question is ICD4.  Because I took a thing naming class at a community college, you can be absolutely clear that this is the fourth ICD input.  When nothing is connected to Read more…

Blab, Hardware, Software, The Home Automation System

2017-12-30

2017-12-30

Note: I was wrong in the last post. It’s the dsPIC that has a broken UART, not the PIC24. For the last month I have been doing the very unsexy work of grinding out bugs in the code. As I hinted at before my software stack had issues under load. I chose to test the full stack (hardware and software) by subjecting it to a completely unrealistic load. The logic behind it is that the Read more…

Blab, Hardware, Software, The Home Automation System

2017-11-18

2017-11-18

I have been working on finishing up the software related to the board. The only feature that I had left on my wish-list was implementing the calibration stuff. The goal was to have the calibration offset be stored in EEPROM and for it to be adjustable via the text/cli interface and via the binary protocol. The process was going to touch the graphical interface piece, the middle-ware that sits between the interface and the board, Read more…

Hardware, The Home Automation System

2017-10-01

2017-10-01

Today I was working on my power and serial expansion board for the Beagle Bone Black. This board provides 5VDC to the BBB, breaks out the RS-232 ports, and sequences (or is supposed to anyways) the power to the RS-232 transceivers and the IO board. All that because the BBB can not have any power applied to any of its input pins until a specific pin goes high indicating that the processor has found its Read more…

Blab, Hardware, The Home Automation System

2017-07-18

2017-07-18

So many failures, so little time More failures. Apparently the driver IC I chose to drive the digital outputs is an N-channel driver. Naturally I had it trying to switch +24V. I know what you’re saying: hey Vic, you stupid, you’ll need a charge pump in order to bring the gate voltage above the source voltage. I did not have nor am I willing to incorporate a charge pump. Another failure was failing to properly Read more…

Hardware, The Home Automation System

2017-06-12

2017-06-12

With all this extra time on my hands while waiting for the PCB to come back, instead of working on the house, playing with the dog, interacting with family, or doing a push-up I decided to test some of the circuitry I’ve already sent off for fabrication. The portion of the circuit under test this time was the the over-voltage crowbar circuit. The basic idea is that if the voltage goes above spec, 5.5V for Read more…

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