Template converting ASCII to HEX or Decimal

Configuration
1

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!

2 
{% 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 itā€™ll work.

3

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

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

Result is 175

4

only now I noticed the forum didnā€™t post my ā€˜arrowā€™ symbol
value_json is the value I have been trying to convert.

@septillion, hereā€™s a result of your template

Screenshot from 2021-05-04 11-08-36
Screenshot from 2021-05-04 11-08-36825Ɨ307 16.4 KB

5

What is that arrow? The ā€œ}ā€ character is ASCII 125, so if you do a |replace to remove the arrow and then use my lookup suggestion above, youā€™ll get the answer you want. Hereā€™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.

6

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.

7

Screenshot from 2021-05-04 11-18-46
Screenshot from 2021-05-04 11-18-46745Ɨ305 17 KB

8

If itā€™s always the first character out of two:

image

and you might find your .encode('ascii') also worksā€¦

1 Like
9

I donā€™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.

10

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

2 Likes
11

Thanks @Troon !

Apparently our ā€œproblemā€ will be addressed here Modbus: uint32 data type Ā· Issue #49941 Ā· home-assistant/core Ā· GitHub
Which was also the reason why I couldnā€™t change datatype and am receiving it in ASCII.

Your first example as been working! Hereā€™s my final config EDP ASCII to Decimal Ā· GitHub

1 Like