Template converting ASCII to HEX or Decimal

[Sthope]

Hi there, I have been trying recently to add a Modbus power meter reader into HA.
But some of the sensors receive the value in ASCII for example } which needs to be converted to decimal 1 125 that represents the real value.

Is it possible to convert from ASCII to Decimal with a Template?

Best results we could archive was using {{ value_json.encode('ascii') }} which converts the result into b'\x01}' but is not the correct.

Any help would be highly appreciated. thanks in advance!

[Troon]

{% set vals="\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b" %}
{{ vals.index('\x05') }} <-- example, returns 5

Obviously, continue the control characters up to \x1f and then through the ASCII characters as far as you need. A bit messy and longwinded, but it’ll work.

[septillion (Timo)]

Think you can use the int filter set to base 16.

{% set foo = "AF" %}
{{ foo|int(base=16) }}

Result is 175

[Sthope]

only now I noticed the forum didn’t post my ‘arrow’ symbol
value_json is the value I have been trying to convert.

@septillion, here’s a result of your template

[Troon]

What is that arrow? The “}” character is ASCII 125, so if you do a |replace to remove the arrow and then use my lookup suggestion above, you’ll get the answer you want. Here’s the full version running out to ASCII 127:

{% set vals = "\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f !\"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\x7f" %}
{{ vals.index("}") }}

That returns 125.

[Sthope]

I cannot remove the arrow as is part of the value it represents 01 in Hex, convert hex 017d to ascii here Hex to Ascii (String) Converter to see the arrow.

[Sthope]

[Troon]

If it’s always the first character out of two:

and you might find your .encode('ascii') also works…

[septillion (Timo)]

I don’t know why you store the register as a string. Why not set the datatype to int when you read Modbus? Than the conversion is done for you.

[Troon]

As noted by @dj-eon in a recent topic, {{ '}'|ord }} will return 125.

[Sthope]

Thanks @Troon !

Apparently our “problem” will be addressed here Modbus: uint32 data type · Issue #49941 · home-assistant/core · GitHub
Which was also the reason why I couldn’t change datatype and am receiving it in ASCII.

Your first example as been working! Here’s my final config EDP ASCII to Decimal · GitHub