Declare int8_t in python

[jon]

I'm using the s130 SoftDevice on the nRF51 dongle and writing a PC app in python. How can I declare an int8_t in python for use in the sd_ble_gap_rssi_get function? The function parameters are:

[in]       uint16_t  conn_handle    Connection handle.
[out]     int8_t *   p_rssi               Pointer to the location where the RSSI measurement shall be stored.

I can declare a uint8_t with the new_uint8t() function, but there doesn't seem to be an equivalent function new_int8t().

[Håkon Alseth]

Hi Jon,

It seems that you have found a bug in our ble_driver python wrapper. Thank you for reporting! We are not handling int8_t, and I have reported this back to our developers.

Have you tried handling it as a new_uint8, then manually converting it to a int8 once you've retrieved the RSSI value (as a temp. workaround)?

Cheers, Håkon

[Pål Håland]

What you can do as a workaround is to convert the uint8 that you receive:

import struct
int_value = struct.unpack("<b", chr(new_uint8))

[jon]

I tried this:

p_rssi = ble_driver.new_uint8()
err_code = ble_driver.sd_ble_gap_rssi_get(connection_handle, p_rssi)

But I get a TypeError:

TypeError: in method 'sd_ble_gap_rssi_get', argument 2 of type 'int8_t *'

[jon]

Thanks for the tip, I think you're saying that after I call sd_ble_gap_rssi_get I can convert the uint8 that I receive to a int8? The problem is that I get a TypeError when I call sd_ble_gap_rssi_get with a uint8 as an argument, so I'm not at the stage where I'm receiving any values back yet.