Hi. I have a SUP500F GPS module and it is outputting NMEA sentences which I can see in a terminal or in the SkqTraq software. However I am unable to send any commands to the module. The SkyTraq software always times out with any command. Can’t update the firmware either.
I checked the comms and can see the data reaching the module’s RX pin on a 'scope. I am connected via USB with 3.3V TTL serial levels. Tried another converter (made with a USB AVR and simple code) but it didn’t help.
AI have VBAT tied to VCC which is 3.3V. PSE_SEL low. Any ideas? Thanks.