Gotta watch these PICs, they’re out to get you! Think I’ll flash an LED on GP0. Let’s see…
bsf GPIO,0
call delay
bcf GPIO,0
call delay
Hmm, doesn’t work. That’s because GP0 hasn’t been defined as an output. OK…
bcf TRISIO,0
bsf GPIO,0
call delay
bcf GPIO,0
call delay
Hmm, still doesn’t work. That’s because TRISIO is a register in the high bank. We need to switch [...]
Some of my harvested sunlight goes into charging AA batteries using a variety of 12 volt capable battery chargers, some intelligent, some less so. By far the most sophisticated of these is the Maha Powerex MH-C9000 WizardOne Charger Analyser. I thought I might say a few words about it.
Most intelligent battery chargers use a combination of voltage, [...]
Continue reading about Maha Powerex MH-C9000 WizardOne Charger Analyser Review
Another consequence of having the FET on the high side of the load is that we need a high voltage supply to drive the FET gate. In previous tests, it was found that the FET would turn on with as little as 4.5 volts on its gate (with respect to its source), but the datasheet [...]
Here’s the circuit for battery voltage measurement. The zener diode (1N959B) drops 8.2 volts off the battery voltage to bring it closer to the 5 volt range that the microcontroller A/D converter can measure. The potential divider provides a further reduction and defines the maximum measurable battery voltage. The 1n5 capacitor smoothes out ripples caused by PWM [...]
Continue reading about Measuring Battery Voltage (revisited)
Centre stage is the PIC12F683
Just spent the last two hours measuring the reverse voltage of a couple of hundred 1N959B zener diodes. These came from a shop sale a few years ago and until recently I wasn’t actually sure what they were. Turns out they’re 8.2 volt zener diodes, 500mW, 5%. Well correct me if I’m wrong, but this means [...]