nRF51822 Tx power not able to set

sunilhalvi gravatar image

asked 2017-05-19 14:04:14 +0100

Hello iam using softdevice 110 and SDK 10.0.0, Iam trying set tx power of nrf51822 using function sd_ble_tx_power_set(), i have tried 0dBm and 4dBm both are giving same RSSI and range, is it really configured or not how to confirm? The API is returning NRF_SUCCESS. Is there any pre-condition to set tx power? And i would also like to know when does GATT error 0x85 occurs, when i try to communicate from 20-30 meters this error occurs and bonding information is lost on central side(may be central is going out of range). Is there any way to avoid GATT error 0x85, because if central bonds again the peripheral is again storing bonding information in eeprom.

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Kristin gravatar image

answered 2017-05-22 13:02:43 +0100

For the range to increase, the TX power have to be increased. However, when increasing the TX power, the RSSI should increase.

What kind of hardware do you use? Our development kit, or a custom board?

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Iam increasing TX power and my code is working fine in Development kit, but in custom board range is lesser compared to development board. What may be the problem?

sunil kumar ( 2017-05-23 13:49:15 +0100 )editconvert to answer

The difference is most likely related to tuning. Our development kit is tuned, so that it will have good output power. If your board is not tuned, the output power will be lower. In addition, if your board hasn't been tuned, there may be a difference in how well it works with various output power.

I don't know what your board looks like, but for good performance, it is crucial to copy our reference layout. It can be useful to have a look at the tutorial "General PCB design guidelines for nRF51 series".

Kristin ( 2017-05-23 15:33:58 +0100 )editconvert to answer

Sunil - When I first read your problem, my immediate thought was also the possibility of a badly tuned antenna circuit.

Kristin didn't mention this, but you can submit a Support Ticket to have one of Nordic's engineers review your antenna circuit design. If you work with them via the Support Ticket process, they will keep everything you provide them confidential.

We did a device that was basically a Nordic development board (reference design) with some parts removed and/or moved around for convenience. Our board layout person had not done much RF work and our device performed miserably. It was so bad, that we couldn't tune the antenna circuit.

We put in a Support Ticket for a review of our antenna circuit and got back some very good information. In fact, at one point the engineer simply made changes to the Altium files we sent him.

The ...(more)

ta2 ( 2017-05-24 09:53:22 +0100 )editconvert to answer

thank you ta2, that was very helpful.

sunil kumar ( 2017-05-24 14:09:26 +0100 )editconvert to answer

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Asked: 2017-05-19 14:04:14 +0100

Seen: 150 times

Last updated: mai 22 '17