Invalid characteristic value

[klonk]

Hello

I started to rewrite hud to more compact esp32 ttgo.

I successfully run in with different display driver , drawn sygic logo and connect to application ( ios , setting , enabled ble hud )

Inside console log , i see

Forming a connection to 7c:39:5e:be:57:c8

• Created client
• Connected to server
• Found our service
• Found our characteristic The characteristic value was: 3
• Found our characteristic Lanes
• Found our characteristic We are now connected to the BLE Server. Read characteristic PING value: "3" writing "connect" loop() start Read characteristic PING value: "2" loop() start Read characteristic PING value: "2" loop() start Read characteristic PING value: "2" loop() start Read characteristic PING value: "2" loop() start Read characteristic PING value: "2" loop() start Read characteristic PING value: "2" loop() start Read characteristic PING value: "i"  loop() start Read characteristic PING value: "i"

So if understand it correctly , 3 is connected to app , 2 is no route and i___ is direction, but wrong single char value always came in ( even when i simulate route ). Is there special version of ios app that support it ? I am currently on 18.7.0 build R-6

Inak paradna praca :)

[alexanderlavrushko]

@klonk , you've done great job with TTGO! I'm happy to see somebody made it work on another device. From what I see in your log, everything works fine:

please check some data details in this comment: https://github.com/alexanderlavrushko/BLE-HUD-navigation-ESP32/issues/1#issuecomment-613968013

the 'i' response is read in BLEMasterNavi1_rgb.ino line 392, the second byte is "flags" - one byte with a set of binary flags:

• bit 0 (value & 0x01) - data contains instruction (e.g. turn right)
• bit 1 (value & 0x02) - data contains speed limit on the current street
• bit 2 (value & 0x04) - data contains the distance to the instruction
• bit 4 (value & 0x10) - lane assistant data is available, but need to read another characteristic

My current implementation checks only bit 4 of these flags, other values are read if valueOffset < dataSize: https://github.com/alexanderlavrushko/BLE-HUD-navigation-ESP32/blob/5cf7173a61d4f1b45b43fcf6a4ab6ea506acd3a3/BLEMasterNavi1_rgb.ino#L410

I know it would be better to write this information in Readme, maybe one day I'll make a proper Readme.

Dakujem :)

[klonk]

Thank you for clarification of flag system. Is there some debug flag to set on inside sygic to see navigation data in "Play mode " as you shown on video ?

All i get is 0 speed, 0 distance and 255 direction ( in play route mode )

[alexanderlavrushko]

Probably it means "no license". If trial is expired, and no premium license, the application stops the instructions service, so instructions are not shown on the phone, not spoken with voice, and not shown on the HUD.

[jaksatomovic]

is there any documentation from sygic where i can see all data examples app will send?

[alexanderlavrushko]

No, there is no official documentation for this experimental feature.

[jaksatomovic]

can you pleaase explain then how does this works

0x690732083335306D00 meaning: instruction (0x69), turn right (0x08) in 350m (0x3335306D00), current speed limit is 50km/h (0x32)

i trying to compare this to your enums in code - instruction (0x69), turn right (0x08)

[alexanderlavrushko]

@jaksatomovic your data example is from the old version (see branches, tag v0.1.0) and it's not compatible with current Sygic app. Since v0.2.0 the data format has changed, and it's the current format. See latest data example here https://github.com/alexanderlavrushko/BLE-HUD-navigation-ESP32/tree/main#technical-info