ANT Forum

Hello everyone,

I am conducting some analysis on the ANT+ protocol and I would like to ask for some clarifications regarding it.
We are performing control tests with both a "Garmin ebike remote" and a "Garmin edge explore". While testing with SimulANT+ set as an LED device, I noticed that they send a command formatted differently regarding the level of assistance to use. To change the level, page 16 is sent, but the fourth byte does not seem to comply with the protocol.
Here is how the data is read by SimulANT from Garmin ebike remote:
22701546 : Rx (Ack): [10][FF][EF][68][00][FC][DC][F5]
22703546 : Rx (Ack): [10][FF][EF][58][00][FC][DC][F5]
22706546 : Rx (Ack): [10][FF][EF][50][00][FC][DC][F5]
22709546 : Rx (Ack): [10][FF][EF][48][00][FC][DC][F5]
22711046 : Rx (Ack): [10][FF][EF][48][00][FC][DC][F5]
22713546 : Rx (Ack): [10][FF][EF][50][00][FC][DC][F5]
22715546 : Rx (Ack): [10][FF][EF][58][00][FC][DC][F5]
22717781 : Rx (Ack): [10][FF][EF][68][00][FC][DC][F5]
22719796 : Rx (Ack): [10][FF][EF][78][00][FC][DC][F5]

Here is how the data is read by SimulANT from Garmin edge explore:
22932546 : Rx (Ack): [10][FF][FF][38][00][00][01][00]
22937796 : Rx (Ack): [10][FF][FF][28][00][00][01][00]
22939546 : Rx (Ack): [10][FF][FF][18][00][00][01][00]
22941546 : Rx (Ack): [10][FF][FF][10][00][00][01][00]
22944046 : Rx (Ack): [10][FF][FF][08][00][00][01][00]
22947546 : Rx (Ack): [10][FF][FF][00][00][00][01][00]
22958546 : Rx (Ack): [10][FF][FF][08][00][00][01][00]
22965046 : Rx (Ack): [10][FF][FF][10][00][00][01][00]
22967296 : Rx (Ack): [10][FF][FF][18][00][00][01][00]
22969796 : Rx (Ack): [10][FF][FF][28][00][00][01][00]
22972046 : Rx (Ack): [10][FF][FF][38][00][00][01][00]
22984796 : Rx (Ack): [10][FF][FF][28][00][00][01][00]


In particular, it appears to me that the "Garmin edge explore" correctly sends the data, while the "Garmin ebike remote" sets the 7th bit of the fourth byte, which should be "reserved, set as 0".

Please could you help me?      

Dear Ian,
please take a look carefully at the "travel mode byte" sent by both devices:

Garmin ebike remote is sending:
22701546 : [68]
22703546 : [58]
22706546 : [50]
22709546 : [48]
22711046 : [48]
22713546 : [50]
22715546 : [58]
22717781 : [68]
22719796 : [78]

while Garmin edge explore is sending:
22932546 : [38]
22937796 : [28]
22939546 : [18]
22941546 : [10]
22944046 : [08]
22947546 : [00]
22958546 : [08]
22965046 : [10]
22967296 : [18]
22969796 : [28]
22972046 : [38]
22984796 : [28]

it appears that the "Garmin edge explore" correctly sends the data, while the "Garmin ebike remote" sets the 7th bit of the "travel mode byte", which should be "reserved, set as 0".      

haighi - 03 April 2023 09:48 AM

byte 2 bit 4 set to 1 indicates that bytes 6 and 7 are man ID, set to 0 indicates that they are a controller ID (lower 2 bytes of ESN). See "ID Type" in SimulANT+.

sorry but I think that these informations are not included in the ANT LEV profile document.
In the ANT LEV profile document the bits 4-7 of byte 2 are marked as "reserved, seto to 0xF value".
Please could you be more clear about that?      

haighi - 03 April 2023 09:58 AM

These are not documented in the profile document. Only SimulANT+.

Please could you send me an updated document?
I need to work on the updated documentation to develop working product.
At the moment the only available document is ANT+ Device Profile rev 1.1 released on November 2011.
I think that it is really outdated.      

haighi - 03 April 2023 02:20 PM

That is the most up to date document.

Dear Ian,
It is not updated because in that document there is no information about bit 6 and bit 7 of byte 4 of page 16.
To develop the firmware we need to know what data to put into profile pages and it is absurd that ThisIsAnt has never updated the documentation even after 10 years.

Please could you check my screenshot and answer me fully.
     

haighi - 03 April 2023 02:20 PM

That is the most up to date document.

Hello there? are you still supporting us?      

Sorry, but is it clear for thisisant that those bits are not "reserved" but are used by some products?
So not only i have to parse them to handle them properly, also the LEV Profile is outdated.