On EN leg is only pull up resistor and LP3992.
SQ1TAO wrote: ↑Thu Feb 08, 2024 11:55 amOn EN leg is only pull up resistor and LP3992.
In your scenario fault may can short to ground or pull to 3.3 from regulator gd77. In my case I connect module to 3.3V rail.
In this application (vdd to module from 3.3v rail gd77) this LP3992 is obsolete, but we can use is as power switch.
In my case I NOT lift 3 leg on LP3992. Maybe your module is loop in on and off again and again... on GP-02 pcb is only pull up resistor connected to this leg. My gd77 still works and CPU without problem drive 3 leg to ground and power out GP-02 without fail.SP2AM wrote: ↑Wed May 29, 2024 10:54 amAlso added GP-02 module to my GD-77:
- for powering on/off GPS I used voltage regulator that's already on GP-02. In my case it had different markings that LP3992 but was compatible. I lifted pin 3 up (EN), put kapton tape under pin to isolate it from PCB pad and connected pin 3 to pin 97 of mcu (green on download/file.php?id=1938 )
https://docs.ai-thinker.com/_media/gp-0 ... ations.pdf
- pin 99 (yellow) to TX pin on GPS-02 module
- 3.3v and GND from the same regulator as download/file.php?id=1935
- also had to mill case a bit and also mill small slots for antenna cable and the rest of wires
- gps antenna needs to protrude from metal case as much as possible; otherwise I wasn't been able to get any satellite coverage
- obviously forgot to insert battery connector gasket (orange one) when assembling and had to disassembly again
The result isn't great. Can't say it works. It finds 1-3 satellites with low signal, then looses them, find some again etc. That's when testing outside. No satellites found inside. Probably that antena (8x8x4mm) is still not exposed enough or just too small?
From what I can remember the only unused pin which supported UART Rx was pin 99do1kka wrote: ↑Mon Jun 24, 2024 9:02 amHi!
I tried yesterday to add a GP-02 GPS module to my GD77 and the module was recognized so far by the device. Because I was not able to catch any satellites, so I decided to open up the device again und put the antenna more outside of the metal frame. Unfortunately, while opening the device, pin 99 of the MCU broke off...
Is it technically possible to use another pin of the MCU as RX for the GPS module (I could try to adapt the source code if necessary), or is this the only possible RX pin?
Thanks in advance for any information!
