ESB rf channels - recommended to be 2 to 81 - how do they map to BLE channels

[Mahendra Tailor]

Hi

I have an application where ESB will be used in the same environment as a few BLE devices which are also our devices.
My plan is to set an rf_channel for ESB and then at the same time set the channel map in BLE to avoid that channel.

I have looked, but I cannot find  any documentation which correlates 'channel' parameter in the api function nrf_esb_set_rf_channel().

It feels as if 'channel' in ESB is 1MHz wide.

I look forward to hearing from you and thank you in advance.

Kind regards
Mahendra

[Kenneth]

Hi Mahendra,

You may look at this:

BT	ESB
37	2
0	4
1	6
2	8
3	10
4	12
5	14
6	16
7	18
8	20
9	22
10	24
38	26
11	28
12	30
13	32
14	34
15	36
16	38
17	40
18	42
19	44
20	46
21	48
22	50
23	52
24	54
25	56
26	58
27	60
28	62
29	64
30	66
31	68
32	70
33	72
34	74
35	76
36	78
39	80

BT ch 37, 38, and 39 are advertising channels.

[Mahendra Tailor]

Hi Kenneth.
That is perfect. Looks like ESB channels were originally designed to be 1MHz wide.

However, you can select bitrate to be NRF_ESB_BITRATE_1MBPS_BLE  and NRF_ESB_BITRATE_2MBPS_BLE
In that case how do you specify the channel?



Also another slightly unrelated question.
There is something called retransmit_delay and the example shows value of 250 and 600.
I have looked and I cannot find which units this are in. Milliseconds or microseconds?

Look forward to hearing from you.

[Kenneth]

Hi again,

The table below is the center frequency for the ESB (e.g. 2 = 2402MHz). The the deviation (to transmit 0 and 1) depends on the data-rate (e.g. 1Mbps = +-160kHz, and 2Mbps = +-320kHz relative to the center frequency).

The retransmit delay is in us, and I expect you mean 500 instead of 600.

Best regards,
Kenneth