TheBackShed.com

Forum Index : Microcontroller and PC projects : Picomite and GNSS 7 GPS

Author

Message

cdeagle
Senior Member

Joined: 22/06/2014
Location: United States
Posts: 265

Posted: 04:24pm 14 Oct 2021

Copy link to clipboard

Print this post

I'm trying to use the GNSS 7 Click board with the Picomite. The GNSS 7 is one of the more advanced NEO-M9N ublox modules and includes Tx and Rx pins and an I2C interface.

I have used it successfully with an Arduino and the I2C interface. However I cannot get it to work with the Picomite via the TX/RX connection using the default 9600 baud. I would appreciate any suggestions about how to make this work.

David

JohnS
Guru

Joined: 18/11/2011
Location: United Kingdom
Posts: 4044

Posted: 04:40pm 14 Oct 2021

Copy link to clipboard

Print this post

I guess it's partly a matter of what have you done & what happened:
1. electrically
2. software-wise

John

matherp
Guru

Joined: 11/12/2012
Location: United Kingdom
Posts: 10315

Posted: 05:36pm 14 Oct 2021

Copy link to clipboard

Print this post

Please try the following and report findings

Connect module TX to pin 2 of the Picomite
Connect module RX to pin 1 of the Picomite

setpin 1,2,com1
open "com1:9600" as gps,0,1

cdeagle
Senior Member

Joined: 22/06/2014
Location: United States
Posts: 265

Posted: 09:28am 15 Oct 2021

Copy link to clipboard

Print this post

Here is a picture of the Picomite/GNSS 7 setup.

The following is a listing of the main MMBASIC code (without subroutines) including Peter's suggestion.

Option autorun 1

' Picomite GPS October 14, 2021

''''''''''''''''''''''''''''''''''''

Font 4

Dim month$(12) As string

month$(1) = "January"
month$(2) = "February"
month$(3) = "March"
month$(4) = "April"
month$(5) = "May"
month$(6) = "June"
month$(7) = "July"
month$(8) = "August"
month$(8) = "September"
month$(10) = "October"
month$(11) = "November"
month$(12) = "December"

' initialize com1

SetPin 1, 2, com1

Open "com1:9600" As gps, 0, 1

Colour RGB(yellow), RGB(black)

' time zone

tzone = 5

' DST (1 = yes, 0 = no)

dst = 1

Do

If GPS(VALID) = 1 Then

tmp1$ = GPS(date)

tmp2$ = GPS(time)

' convert calendar date to month-day-year

gps1$ = month$(Val(Mid$(tmp1$,4,2))) + " " + Mid$(tmp1$,1,2) + ", " + Mid$(tm$,7,4)

gps2$ = GPS(time)

' extract utc hours, minutes and seconds

ut_hrs = Val(Mid$(tmp2$, 1, 2))

ut_min = Val(Mid$(tmp2$, 4, 5))

ut_sec = Val(Mid$(tmp2$, 7, 8))

lct_hrs = ut_hrs + ut_min / 60.0 + ut_sec / 3600.0 - tzone + dst

hrs2str(lct_hrs, lct_hms$)

dd_lat = GPS(latitude)

deg2str(dd_lat, gps3$)

dd_long = GPS(longitude)

deg2str(Abs(dd_long), gps4$)

CLS

If (dd_lat > 0.0) Then

NS$ = " N"

Else

NS$ + " S"

EndIf

If (dd_long > 0.0) Then

EW$ = " E"

Else

EW$ = " W"

EndIf

Text 5,20, "DATE " + gps1$

Text 5,40, "LCT " + lct_hms$

Text 5,60, "UTC " + gps2$

Text 5,80, "LAT " + gps3$ + NS$

Text 5,100, "LON " + gps4$ + EW$

Text 5,120, "ALT " + Str$(Int(GPS(altitude))) + " meters"

Text 5,140, "SPD " + Str$(GPS(speed)) + " knots"

Text 5,160, "TRK " + Str$(GPS(TRACK)) + " degrees"

Text 5,180, "FIX " + Str$(GPS(fix))

Text 5,200, "DOP " + Str$(GPS(DOP))

Text 5,220, "NSAT " + Str$(GPS(satellites))

Else

CLS

Text 5, 20, "INVALID GPS DATA"

EndIf

Pause 30000

Loop

The code resides in FLASH 1.

When the code runs and I monitor via Teraterm, lots of strange characters appear on the screen.

Volhout
Guru

Joined: 05/03/2018
Location: Netherlands
Posts: 5091

Posted: 09:57am 15 Oct 2021

Copy link to clipboard

Print this post

Some idea's:

1/ For the UART to work, you need to pull the D_SEL pin high (the pin is called "AN" in the microbus module silkscreen)
2/ The baudrate can be anything between 4800 and 900kbaud. Maybe it is set default to 4800baud.

Regards,

Volhout
Edited 2021-10-15 19:58 by Volhout

PicomiteVGA PETSCII ROBOTS

matherp
Guru

Joined: 11/12/2012
Location: United Kingdom
Posts: 10315

Posted: 12:17pm 15 Oct 2021

Copy link to clipboard

Print this post

Quote When the code runs and I monitor via Teraterm, lots of strange characters appear on the screen.

Sounds like the PicoMite UART input may be inverted. Try a npn in the TX line from the GPS

cdeagle
Senior Member

Joined: 22/06/2014
Location: United States
Posts: 265

Posted: 01:05pm 15 Oct 2021

Copy link to clipboard

Print this post

Thanks for the suggestions.

Good things to try to keep my mind from turning to mush.

JohnS
Guru

Joined: 18/11/2011
Location: United Kingdom
Posts: 4044

Posted: 02:01pm 15 Oct 2021

Copy link to clipboard

Print this post

When nothing's being sent you could look at the volts on Tx/Rx to see pretty surely whether their signals are inverted.

John

Print this page

To reply to this topic, you need to log in.