July 9th, 2019, 9:29 am
sudo screen /dev/ttyS0
sudo screen /dev/ACM0
July 10th, 2019, 5:49 pm
MadAEng wrote:Does anyone have any clues on where the problem may lie?
July 11th, 2019, 5:45 am
valamilamasag wrote:MadAEng wrote:Does anyone have any clues on where the problem may lie?
Yes. You just killed the serial port on the botvac in the best case or did unknown amount of other damage to SOC.
Its a 3.3V TTL serial on the botvac, you could have just connected directly to the PI with two 1kohm resistors.
The MAX3232 creates RS232 level voltages which are up to +-15V (30V swing). The SOC on the botvac operates at 3.3V IO voltage and 1.8V (or 1.2V) core voltage, thus anything under 0V (MAX3232 outputs -15V) or over 3.3V (MAX3232 outputs +15V) will damage the SOC.
July 14th, 2019, 1:04 pm
MadAEng wrote: wish someone told me that sooner....
Yesterday, 7:19 am
valamilamasag wrote:MadAEng wrote: wish someone told me that sooner....
You were told in the other thread. There are countless posts here about that debug interface. You could have easily measured it too, even with a 1 dollar multimeter. Or read what RS232 is and from the measurements quickly determine that it is not RS232.
Alongside where you got the picture in the first post, there is a description about the interface. But pictures look pretty and reading is tiring right?
But I'm curious, did you managed to kill it? Or did one of the ESD/TVS diodes shorted itself and protected the SOC? MAX3232 can only supply a few mA (maybe 15) which if you are lucky sinked away by the protection diodes and dumped into the power line of the SOC.
Yesterday, 10:24 am
Yesterday, 1:18 pm
read what RS232 is and from the measurements quickly determine that it is not RS232.
Yesterday, 1:49 pm
MadAEng wrote:fix it
Yesterday, 4:06 pm
Yesterday, 5:46 pm
Yesterday, 6:15 pm
Today, 6:03 am
valamilamasag wrote:If you measure a short to the 3.3V or the GND pin from TX or RX then you are not in luck. Those diodes are inside the SOC. That can't be replaced, only the whole SOC. It requires an infrared pre-heater, a hot air soldering station and the component (SOC) itself cant be sourced either.
Do the measurements in both direction in the diode mode of your meter (measures the forward voltage of a diode). 0.5-0.7V or open circuit (or above ~3V) readings are normal, anything under 0.3V is highly likely a short circuit. Above 0.7V readings does not mean a problem, but could be a sign also. The robot should not have any power during measurements.
27 minutes ago
MadAEng wrote:0.647 and 0.547
MadAEng wrote:sky is the limit
MadAEng wrote:esp vs camera