CSP Interfaces¶
The Polaris receiver is operated remotely via CubeSat Space Protocol (CSP) messages. The Polaris ADS-B Client Library, Property Client Library, and BTP Client Library all contain wrapper function around CSP protocols. In addition, Polaris also implements the standard CSP service ports such as CSP_PING
and CSP_REBOOT
.
Configuration CSP parameters¶
By default, the receiver uses address 23
but this can be changed by adjusting the address property sys.csp.address
and saving the sys
group. The system must be rebooted for the address change to take effect.
The receiver supports CSP via CAN-bus (CAN
interface) and RS-422 (KISS
interface) in the P1 connector. Both interfaces are always enabled for incoming messages, but the default routing table sends egress messages on the CAN interface for all traffic except loopback. The interface rates can be set using the sys.can.rate
and sys.uart.rate
properties. By default, the RS-422 interface is configured for a point-to-point link. By setting the sys.uart.multidrop
property to true
the interface can be configured for multidrop mode where the output is only driven when actively transmitting.
The current routing table can be listed using the csp route show
command in the debug shell:
[polaris] csp route show
20/5 LOOP
0/0 CAN
The results are listed using CIDR notation. CSP addresses are 5 bits long so, 20/5
is an exact match to address 20
, i.e. the loopback address. 0/0
marks the default route. To adjust CSP routing, the sys.csp.routes
property should be used. As an example, to send all traffic via the RS-422/KISS interface set the property to 0/0 KISS
and save the sys
group. It is not necessary to add an explicit route for the loopback interface.
The CSP connection can be tested using the csp ping
debug shell command. This can be combined with the watch
command to e.g. ping a system 10 times and report the number of successful replies. This example pings address 1 with 100 byte frames:
[polaris] watch -c10 -s csp ping -s100 1
Running command 'csp ping -s100 1' every 1000 ms
Reply in 3.138 ms
Reply in 3.159 ms
Reply in 3.833 ms
Reply in 3.146 ms
Reply in 3.896 ms
Reply in 3.102 ms
Reply in 3.709 ms
Reply in 3.126 ms
Reply in 3.730 ms
Reply in 3.194 ms
10 executions, 10 success 0 failures