Duplex MMDVM board not working correctly?

[G8SEZ]

You're not being a pain, it's entirely reasonable to be confused.

I note from the schematic of these boards:

https://github.com/phl0/MMDVM_HS_Dual_H ... al_hat.pdf

that the BOOT1 signal is connected to a pin on the ST32F103, and it does have a solder jumper JP1 allowing you to connect it to ground via the series 100k resistor that also connects to the 3x2 header P7. Has this been done?

[K1SEH]

Doesn't appear to have anything soldered or jumpered along those lines.

HS_Hat.png (202.36 KiB) Viewed 7469 times

[G8SEZ]

Two suggestions.

First try changing the duplex value to 1 in the expert config and save it. See if it does anything different.

Second, if nothing has worked so far, try shorting JP1 across its pads and run through the various checks again.

In the HS_HAT schematic the BOOT1 signal on pin PB2 is permanently grounded (it's not called BOOT1 either), in the DUAL_HS_HAT schematic there is a series 100k resistor between the STM32F103 pin PB2 and JP1. I imagine the idea is that if that pin is read it will be a 0, but if the output is asserted high then it will read back a 1. I don't know if that is what the firmware does but I can't see what the BOOT1 signal is for otherwise.

[K1SEH]

OK, I'll try those suggestions. Other than a bit of solder on JP1, I'm not really set up for SMT work, so if your two suggestions don't work, then I'll either just live with it, or possibly find another dual hat somewhere.

Thanks!

[G8SEZ]

I've just read the release information on the DUAL_HAT again. It says, for board version 1.1:

"Solder jumper JP1 was added. It can be closed if the board is used on Raspberry Pi only. It ties BOOT1 to GND. BOOT0 is controlled via GPIO."

Given that this was written by a non-native speaker of English, I think this actually should say "It should be closed if the board is used on Raspberry Pi only."

I can't promise that this will work, but it would seem to be the intention of the designers.

The pads for JP1 are fairly large so all you need is a blob of solder across the V shape between the pads, it should be possible without SM tools.

[K1SEH]

Yup, about to do that now. The other stuff didn't work.

Here goes nothing.
(worse comes to worst, I'll remove/cut the solder blob).

[K1SEH]

Still didn't work. Interestingly enough, though, it still works as it did before, with the solder blob in place. Oh well.

Thanks for the help, anyway!

[K1SEH]

I'll keep mucking with the hat, but I just ordered this as a replacement: https://www.amazon.com/gp/product/B07W4 ... UTF8&psc=1

Best case scenario is that I can pick up another rPi and have two hotspots!

[K1SEH]

It does, but the hotspot no longer hears me, nor I, it.

[K1SEH]

I have two different freqs for TX and RX. The handheld is using those freqs as well (in reverse, obviously).

When I use the "non-dual hat" config, only TS2 is green. but everything works. When I use the dual-hat config, both timeslots are green but I'm not able to communicate with the hotspot.

I'll send pics in two parts. The attached pics show what does work with my handheld. In this instance, only TS2 is enabled (I can't add more than 3 photos to a post.

2020-06-05_16-20-44.png (103.02 KiB) Viewed 7251 times

2020-06-05_16-12-16.png (19.27 KiB) Viewed 7251 times

Part 2 of this reply will have screen shots from what does not work.