CCS/TMS320F28335: Unable to send float values through CAN communication

Gautham Gangula

Part Number: TMS320F28335

Tool/software: Code Composer Studio

Hello all,

I have been using CAN communication between 2 DSP's (TMS320F28335). But when I tried sending the float values through CAN only the integer part is received at the receiving end.

For example: If I send float value, say 48.253, only 48 is received at the other end. I tried separating the integer and float values at the source and then sent the data, but even that was not working. Later I learned that CAN mailboxes are of type Uint32 (Unsigned Integer 32). Do we have a provision to change the data type of these mailboxes?? Or is there any other method through which I can send float values through CAN. Please suggest me a solution.

Thank You!!

over 7 years ago

0 Gautam Iyer over 7 years ago

Guru 192875 points

Hi Gautham,

You cannot send float values over CAN. Generally the float values are multiplied by 10/100/1000 and then sent through CAN. At the receive section the division operation is performed. For more optimization left shift and right shift operations are preferred.

Regards,
Gautam

0 Hareesh Janakiraman over 7 years ago in reply to Gautam Iyer

TI__Guru* 95315 points

Gautham,
The CAN module does not know (or care) about fixed-point or floating point. What it does is to take the data in the mailbox-RAM and transmit them, after adding the needed fields mandated by the protocol (MSGID, stuff bits, CRC etc). Formatting of the data is the concern of the application software, as Gautam pointed out.