RF modules from Hong Kong

Following on from this:- https://www.electro-tech-online.com/threads/ic-components-limited-in-hong-kong.161552/

The components that I bought were Telit GE865 GSM modules, and they worked fine.

A few years later, a second batch appears to be counterfeits. The serial number isn't the right format to be an IMEI, and the RF shielding on the top is one piece, while the previous ones had an open topped frame and a separate metal lid pushed onto the frame.

I've opened one up and it seems to have all the right components in there. However I can't see the multiple vias on the ground plane that the genuine one has, although that could be differences in PCB process, and there are differences in layout, but I don't know how many different versions there were in the genuine ones.

As for how the counterfeit ones behave, I've only tried one so far and it turns on and responds to AT commands, but it just reports a string of zeros as the IMEI. It won't connect to the network and it won't tell me the serial number of the SIM connected to it. I have flashed the latest Telit software to it, and it reports the software version number correctly, but no change in behaviour.

The physical changes I recognize as normal cost reductions. The IMEI and AT response is curious and I wonder what their email support response was.

Tony Stewart said:

The physical changes I recognize as normal cost reductions. The IMEI and AT response is curious and I wonder what their email support response was.

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The date code is older than ones that I have seen before. However I know that these modules have been made in several different countries, so there will have been multiple minor changes in design.

Do you think that I should ask Telit? The modules haven't been made for some years, so I've been buying old stock.

I would assume that Telit would just say that they are counterfeit. I noticed the physical and marking differences as soon as I looked at them.

Certainly share all your info in your question to them about all issues.

Tony Stewart said:

Certainly share all your info in your question to them about all issues.

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Thanks for the suggestion. I already had a login with them to get data sheets and they have told me that the modules are not fakes, but ones awaiting an IMEI to be allocated to them.

I now need to find out how to get hold of IMEIs. It could well be that it's not practical for anyone making less than thousands a day.

I've just tried one with an IMEI from a broken module and it works. The module can receive calls and texts, send texts, go online etc. All I need now is a source of IMEIs that I can use.

Tony Stewart said:

Dial *#06# on the keypad.

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The GSM modules don't have keypads. The IMEI of those is read with an AT command. The actual command is
AT+CGSN
and the module replies with the IMEI and "OK"

It was that command that returned a string of zeros on the modules with no IMEI

Diver300 said:

The GSM modules don't have keypads. The IMEI of those is read with an AT command. The actual command is
AT+CGSN
and the module replies with the IMEI and "OK"

It was that command that returned a string of zeros on the modules with no IMEI

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So how did you manage to add the IMEI to the one you got working?.

It looks like the boards weren't actually finished, you should return them and replace them with finished ones.

Nigel Goodwin said:

So how did you manage to add the IMEI to the one you got working?.

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Seriously? He just said, "AT commands".

ZipZapOuch said:

Seriously? He just said, "AT commands".

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That's how you read it, how do you add one?.

ZipZapOuch said:

Seriously? He just said, "AT commands".

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I did only mention AT commands for reading the IMEI number.

A different AT command is used to program the IMEI number. Apparently it can only be done once.

Nigel Goodwin said:

That's how you read it, how do you add one?.

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Again, with an AT command.

ZipZapOuch said:

Again, with an AT command.

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I hadn't said how I had added an IMEI until after Nigel's question.

Without any way of obtaining 50 IMEIs, the modules that don't have IMEIs are essentially useless. I didn't want to try to register to be able to create my own IMEIs, which would have been at least £500, and it's a process that is aimed at bigger manufacturers, not someone using 50 modules.

Anyhow, I found a supplier on Aliexpress that offered the normal GE865s with IMEIs already allocated at less than £4 each. I bought 20, which seemed to be the maximum number that they wanted to supply to the UK, but was a small enough cost that I could afford it if they didn't work.

They arrived today and I've only tested one, and it worked. I was able to update the firmware to the latest version from Telit and the module connected to the phone network. I had previously made a test board with spring pins so that I can try them and update the firmware without soldering them down, and I used that to check the module.

I will probably buy a few more batches of 20.