Michael,

1. I had the impression we've had more than expected "modem not/stopped working" issues. Is that impression wrong, or didn't those cases share a hardware cause? I was wondering if that could be related to a voltage regulator issue (e.g. https://www.openvehicles.com/node/2855).

I have had just three reports of modem module not working at 12V, but working at 5V. On two, the issue was the power regulator chip blown on the modem board. I don’t think there is anything inherently wrong there - probably just a faulty component or power surge.


2. Any chance to fix the missing HW flow control on the modem UART connection?

I don’t think we have enough GPIOs. Perhaps later when/if ESP32 S3 becomes suitable?

3. Will v3.3 automatically be built using the latest ESP32 WROVER, i.e. with the revision 3 ESP32 including the hardware SPIRAM fix?

They normally build each batch with the latest. I haven’t checked for a while, so will check one from the last batch I received, and let you know. We can request this, but it will depend on stock.

Regards, Mark.

On 17 Aug 2021, at 3:31 PM, Michael Balzer <dexter@expeedo.de> wrote:

Signed PGP part
Mark,

1. I had the impression we've had more than expected "modem not/stopped working" issues. Is that impression wrong, or didn't those cases share a hardware cause? I was wondering if that could be related to a voltage regulator issue (e.g. https://www.openvehicles.com/node/2855).

2. Any chance to fix the missing HW flow control on the modem UART connection?

3. Will v3.3 automatically be built using the latest ESP32 WROVER, i.e. with the revision 3 ESP32 including the hardware SPIRAM fix?

Regards,
Michael


Am 17.08.21 um 07:30 schrieb Mark Webb-Johnson:
For the 4G modem options we need to go through FCC, CE, and ROHS certification. Minimising/eliminating the changes to the main board simplifies this (and brings down the exorbitant costs) but if there is anything urgent / necessary, now is the time to do it.

The goal here is to maintain 100% compatibility with existing OVMS main boards, to keep this is a simple and relatively cheap upgrade of the modem board.

So far, I have come up with this minimal list:

  1. Main board v3.3: Improve soldering of micro USB port. Bigger solder pads, and more solder to secure it better.

  2. Modem board v1.3: Add support for SIM7600 module.

  3. Modem board v1.3: Fix support for DTR sleep/awake support.

Is there anything else required for this update?

Regards, Mark.

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