From the Lab ...

... Hacking and Slashing since 2002

Title: Laird BL600 BLE Bluetooth Low Energy module
Posted by:
Previous: New(er) HP/Agilent/Keysight 8753D
Next: Tektronix 2782 Spectrum Analyzer and the wonky RTC-58321

So we ran into an issue working with a client using this module. Specifically, we couldn't figure out why we were NOT getting full output power (RSSI with Lightblue from only a few feet away was -90dBm). Long story short, Laird has a special whisper mode. If you have similar issues, see this blog post on the Nordic Semiconductor Dev Forums --- https://devzone.nordicsemi.com/question/4629/laird-bl600/ 
 
Lazy? ... to paraphrase: 
 
"It seems Laird uses pin 20 to enable whisper mode, so if it is not explicitly set to low, then you will get terrible RF performance. 
 
Response from Laird: 
 
If you are using the Nordic SDK, the output of GPIO 20 must be set as a low (0v) to enable the RF transmit power circuitry. Your reference to a 10m range is the most commonly reported symptom for this issue. Setting GPIO 20 low is done via the Nordic application that you are using. We instituted GPIO 20 programmatically with smartBASIC however if you are indeed using the Nordic SDK you must set it manually." 
 
Here's an image of what's under the can. You can see a three terminal device in the lower right that goes to GPIO 20 and the PA Enable pin. They are probably throttling the amount of power available to the output stage on the nRF51822, thus limiting the range. 
 
IMG_2358_resize.jpg 


Previous   1   Next