Hello there,
I need to send a float32 value to something via the modbus integration. There exists a limitation within the modbus integration which requires to send the float32 value as two float16 values to work around that limitation. I’ll include the specifics for the off chance, that I missed something and don’t the to use the REST API after all.
The transformation works as follows:
- Convert the float32 value of, for example, 1.3, to the hexadecimal notation compliant with the IEEE 754 standard: 0x3fa66666
- Split the string into two 4 character strings and add a 0x before the second one, resulting in: 0x3fa6, 0x6666
- Send those values via the modbus integration
Performing those operations doesn’t seem possible with the script syntax used by Home Assistant(JINJA?) alone, therefore I defined a shell_command integration in the configuration.yaml, which calls a python script that performs those operations and need a way to return those values:
shell_command:
convert_float_script: 'python3 convertfloat32tofloat16.py {{ float32_value }}'
The script gets called, the path isn’t an issue here.
According to the docs (Shell Command - Home Assistant) for shell commands, the output of that python script is supposed to be usable by defining a response_variable in the script that calls that shell_command and using {{ custom_response[‘stdout’] }} in another service defined in that same script. This simply doesn’t output anything for me, though {{ custom_response[‘returncode’] }} works.
This is my test script:
test_convert_float32:
sequence:
- service: shell_command.convert_float_script
data_template:
float32_value: 1.3
response_variable: custom_response
- service: input_text.set_value
data:
value: "{{ custom_response['stdout'] }}"
target:
entity_id: input_text.float32test
I created a text helper (input_text.float32test) to serve as a temporary display with the capabilty to track changes.
So, since the response_variable approach didn’t work, I tried to go the API route. I reduced the above script to
test_convert_float32:
sequence:
# This is Home Assistant Script Syntax
- service: shell_command.convert_float_script
data_template:
float32_value: 3.6
and modified the python script to not return the values, but to post them to the REST API and change the value of input_text.float32test that way:
url = "http://HOSTIP:8123/api/services/input_text/set_value"
headers = {
"Authorization": "Bearer myToken",
"content-type": "application/json",
}
data = {"entity_id": "input_text.float32test", "value": str(result1) + ", " + str(result2)}
response = post(url, headers=headers, json=data)
This works great when running the python script from a different computer, but doesn’t work when run by the shell command integration. It results in this log entry:
WARNING (MainThread) [homeassistant.components.http.ban] Login attempt or request with invalid authentication from localhost.localdomain (127.0.0.1). Requested URL: '/api/services'. (Python-urllib/3.9)
The token is valid, the script works from a different computer and I even added
http:
use_x_forwarded_for: true
trusted_proxies: 127.0.0.1
to the configuration.yaml in an unsuccessful try to resolve this issue. I also tried to replace the HOSTIP with localhost, same issue. Note that HA is running inside a docker container.
I’m honestly at my wits end here, I simply want to send a float32 value via the modbus integration. Any ideas? What am I overlooking?
