Serial UART to nRF8002 to Bluetooth 4.0 service

RE: Serial UART to nRF8002 to Bluetooth 4.0 service

Peter Burkimsher — Wed, 29 Jan 2014 16:53:06 GMT

Ah, it's locked off after one-time programming? Then I guess there's not much I can do. Thank you for explaining! I'm glad that I correctly understood the datasheet about it not being 5V safe. Even though I'm obviously a bit disappointed that I soldered a beautiful breakout board for the test points, I'm extremely impressed by Nordic's technical support. Seriously - many companies are actively hostile to people modding and tweaking their equipment, but you've been actively helpful in guiding me how to do this correctly! Happy lunar new year!

RE: Serial UART to nRF8002 to Bluetooth 4.0 service

David Edwin — Wed, 29 Jan 2014 16:42:43 GMT

I will be very surprised if the UART lines on the iCookie work, as nRF8002 devices will lock off the UART once they have been production programmed (like in the iCookie). The nRF8002 works between 1.9v to 3.6v it is not 5v safe. You may be able to re-use the button on the iCookie and then interface the button to the scale so when somebody steps on the scale the alert is sent to the phone.

I really do not know the chip in the scale so I cannot comment on it at all. Good luck.

RE: Serial UART to nRF8002 to Bluetooth 4.0 service

Peter Burkimsher — Wed, 29 Jan 2014 16:03:27 GMT

Yes, I will try to persuade my manager to buy more hardware when I've proven that I'm able to use what I have responsibly. Interfacing with the display bits might be easier, because I'm not certain if the epoxied chip is really showing an SPI port, or some other test points.

I really appreciate all the project-specific help, and hope that we can continue to work on this. I've installed nRFgo Studio on the old Toshiba with the DB9 COM port, and the software is working fine. However, I'm afraid to plug it into the current chip I have. I know it's not the final development board we'll be using, but it really would be nice to show something practical to my manager rather than just a comment thread. If the 8002 is 5V safe, all will be well! But please confirm this, because I understand the datasheet to say that it's only able to run at 3V levels.

RE: Serial UART to nRF8002 to Bluetooth 4.0 service

David Edwin — Wed, 29 Jan 2014 15:16:16 GMT

Remember I am talking about the nRF8001 , NOT the nRF8002. You will need to get a BLE shield as stated in the devzone.nordicsemi.com/arduino As for the weighing scale, the last time we hacked at it we intercepted the display (which was displaying the weight) , interpreted it and sent it over the BLE link.

RE: Serial UART to nRF8002 to Bluetooth 4.0 service

Peter Burkimsher — Wed, 29 Jan 2014 14:58:05 GMT

Thank you for the suggestion! I'm pleased to see that it's also supported by the nRFready iOS demo app, and is still low-power. In the morning I'll solder some wires onto the scales I've got, and see if I can make any sense of SPI data. There's a 4-wire header with VDD, Key1, Key2, and GND, which I guess might be SPI. The chip in the scales is all covered in epoxy though, so I can't be certain. Ultimately the final design will be using our own weight sensors and everything, I just want to be able to build a prototype to keep my manager satisfied.

Meanwhile, please can you confirm that plugging in the chip to a DB9 serial COM port is unsafe? I'm pretty sure from the datasheet that 5V would fry the nRF8002, but it would make building the programming circuit much easier.

RE: Serial UART to nRF8002 to Bluetooth 4.0 service

David Edwin — Wed, 29 Jan 2014 14:48:25 GMT

If you are looking at a serial interface you can also look at the nRF8001 that provides a well defined serial interface (SPI) and you can use an Arduino to control the nRF8001. See devzone.nordicsemi.com/arduino Making a weighing scale with Arduino and the nRF8001 should be easy using the nRFgo Studio for nRF8001 configuration.

RE: Serial UART to nRF8002 to Bluetooth 4.0 service

Peter Burkimsher — Wed, 29 Jan 2014 13:13:37 GMT

Although the knowledge applicability is pretty low, it will at least introduce me to nRFgo Studio, and give me something to demo (kind of).

It sounds like the most helpful method would be to interface it with a Windows PC, either a virtual machine on my Macbook Pro or this old Toshiba. Then I can show nRFgo Studio, which will apply to other chips too.

Can you confirm that to use it with my USB-DB9 adaptors, I'll need a serial level converter to bring the voltage down to 3V? I'm just worried about frying the chip.

Thanks for being so prompt, even at this hour! I guess it's a time zone thing :).

RE: Serial UART to nRF8002 to Bluetooth 4.0 service

Ole Morten — Wed, 29 Jan 2014 12:48:55 GMT

You can configure the chip over the serial interface, including changing the name of it. Take a look at the configuration options in nRFgo Studio to see what you can and can't do.

However, you can not change the configuration while it's running, and each time you want to configure it, you'll have to reset the chip, causing it to lose the connection and any bonding information. Honestly, I personally think it would be a waste of effort trying to do this, since the use of it would be so limited, and the knowledge applicability for our other chips so low...

RE: Serial UART to nRF8002 to Bluetooth 4.0 service

Peter Burkimsher — Wed, 29 Jan 2014 12:44:13 GMT

Ole,

Thank you for your quick reply! Even though I'm naturally a little disappointed that it's not possible with the hardware I have, I'm hoping my manager will understand. He chose the iCookie anyway, so it's not entirely my fault ;-). It wasn't a bad investment either, because it led us to your chips! I told him how excellent your documentation and technical support is, and I'm sure he'll be pleased that I got a reply within 5 minutes!

I found the nRF51822, and was very pleased that it's already intended for weighing scales in healthcare applications! He still wanted me to build a prototype to prove my competence, and then he said he'd invest in the development board. Now you say it's impossible, I can move onto the other half (the weighing scale sensor input), and show him what I've got despite this roadblock.

Back to the nRF8002 though - maybe it's impossible to use it as a true serial input, but could I reflash it with a different characteristic value? I was looking at the Device Name (0x2A00), Alert Level (0x2A06) and CCCD (0x2902), because they're Read/Write. It would be a nice little demo to show off, just to prove that my serial breakout actually works.

Peter

RE: Serial UART to nRF8002 to Bluetooth 4.0 service

Ole Morten — Wed, 29 Jan 2014 10:25:26 GMT

I'm sorry to be the bearer of bad news, but this is not possible. The UART interface of the nRF8002 is only usable for DTM testing and configuration of it, and can not be used to transfer custom data in any way. The nRF8002 is a hard-coded system-on-chip for proximity use cases, and you can not extend or change what profiles or services it supports in any way.

I'd strongly recommend you to instead get hold of an nRF51822 kit of some kind, and develop with that. I understand that your 7 days timescale may be problematic, but there isn't really any way you can get the nRF8002 to do what you want.