2nd hardware UART

[rocket_troy]

Apologies, here is the actual code:

OSCFRQ = %1000 '64Mhz

Define OSC 64

PRECISION  CON 8 SYSTEM  '8 byte = 64 bit precision
INCLUDE "N-Bit_Math.pbp"

DEFINE HSER2_RXREG PORTB
DEFINE HSER2_RXBIT 3
DEFINE HSER2_TXREG PORTB
DEFINE HSER2_TXBIT 0
DEFINE HSER2_BAUD 9600

DEFINE HSER_RXREG PORTC
DEFINE HSER_RXBIT 4
DEFINE HSER_TXREG PORTC
DEFINE HSER_TXBIT 5
DEFINE HSER_BAUD 9600
 
ANSELA = %00000000 'Everything Digital
ANSELB = %00000000 'Everything Else Digital
ANSELC = %00000000 'Everything Else Digital

TRISB.0 = 0 
TRISB.3 = 1 
TRISC.4 = 1 
TRISC.5 = 0 

'works
hSerout ["Test",13,10]

'doesn't work
hSerout2 ["Test",13,10]

[robertg]

I'm far from an expert in this space. And haven't used the second USART port on a PIC
But maybe PMD5 register for UART2 isn't being set correctly by picbasic??

bit 5 U2MD: Disable UART2 bit
1 = UART2 module disabled
0 = UART2 module enabled
bit 4 U1MD: Disable UART1 bit
1 = UART1 module disabled
0 = UART1 module enabled

[richard]

I'm far from an expert in this space. And haven't used the second USART port on a PIC
But maybe PMD5 register for UART2 isn't being set correctly by picbasic??

extremely unlikely

note power on defaults for PDM5


did you try setting uart regs like mcc suggests ?
note uart registers

[rocket_troy]

Regarding setting the regs directly: this is what I've tried (note this is set to 115200 baud as that was the original objective)

OSCFRQ = %1000 '64Mhz

Define OSC 64

PRECISION  CON 8 SYSTEM  '8 byte = 64 bit precision
INCLUDE "N-Bit_Math.pbp"

'Use for hardware serial comms to SD card module
'******************************************************************************
'Configure UART Control Register 0
U2CON0.7 = 1 'BRGS = 1 (high speed baud generator)
U2CON0.6 = 0 'ABDEN = 0 Auto-baud Detect Disabled 
U2CON0.5 = 1 'TXEN: Transmit Enabled
U2CON0.4 = 1 'RXEN: Receive Disabled
U2CON0.3 = 0 '0000 = Asynchronous 8-bit UART mode
U2CON0.2 = 0 '0000 = Asynchronous 8-bit UART mode
U2CON0.1 = 0 '0000 = Asynchronous 8-bit UART mode
U2CON0.0 = 0 '0000 = Asynchronous 8-bit UART mode

U2CON1.7 = 0 'Turn Serial port 2 off for baud setting
 
U2BRGL = 138  'Baud Divisor low byte
U2BRGH = 0    'Baud Divisor high byte

U2RXPPS = %1011 'Assign UART RX pin to RB3
RB0PPS = %010110  'Assign UART2 TX pin to RB0
 
U2CON1.7 = 1 'Turn Serial port 2 on
'******************************************************************************
 
'Configure AN2 as Analog Inputs (PortA2)
ANSELB = %00000000 'Everything Digital

TRISB.0 = 0 'SD_Card_TX Hardware UART
TRISB.3 = 1 'SD_Card_RX Hardware UART

hSerout2 ["Test",13,10]

That doesn't provide any joy either.

[HenrikOlsson]

I was going to say that you need to unlock the PPS before trying to configuring it but reading the datasheet it looks like it is unlocked at POR - I've always thought it was the other way around.

Anyway, here's the relevant parts from a project of mine which uses both UARTS, in this particular case I even use the PPS peripheral to switch UART2 pins around to two different devices. Using HSEROUT / HSEROUT2 in the code it worked out fine. This is for a 67K40 so it won't match your setup but perhaps it can provide some pointers.

'----------------------------------------------------
' PPS Unlock
PPSLOCK = $55
PPSLOCK = $AA
@ BCF PPSLOCK, PPSLOCKED

RC6PPS = $0C                                ' We want PORTC.6 as EUSART1 TX
RX1PPS = %00010111                          ' We want PORTC.7 as EUSART1 RX

RG7PPS = $0E                                ' We want EUSART2 TX on PortG.7 
RX2PPS = %00110010                          ' We want EUSART2 RX on PortG.2 

' Since we're switching UART pins around during runtime we need to leave the PPS lock open.
'PPSLOCK = $55
'PPSLOCK = $AA
'@ BSF PPSLOCK, PPSLOCKED
'----------------------------------------------------

ANSELA = %00110000                          ' RA4, 5 analog, rest digital 
ANSELB = 0
ANSELD = 0
ANSELE = 0
ANSELF = 0
ANSELG = 0


' Setup for EUSART1 
RCSTA1 = $90                                ' Enable serial port & continuous receive
TXSTA1 = $24                                ' Enable transmit, BRGH = 1
SPBRG1 = 64                                 ' 19200 Baud @ 64MHz, 0,04%
SPBRGH1 = 3
BAUDCON1.3 = 1                              ' Enable 16 bit baudrate generator


' Setup for EUSART2 
RCSTA2 = $90                                ' Enable serial port & continuous receive
TXSTA2 = $24                                ' Enable transmit, BRGH = 1
SPBRG2 = 138                                ' 115200 Baud @ 64MHz, -0,08%
SPBRGH2 = 0
BAUDCON2.3 = 1                              ' Enable 16 bit baudrate generator


TRISC.6 = 0                                 ' UART1 TX
TRISC.7 = 1                                 ' UART1 RX

TRISG.7 = 0                                 ' UART2 TX 
TRISG.2 = 1                                 ' UART2 RX

/Henrik.

[rocket_troy]

Thanks Henrik,
I'll see if there's anything there that I've maybe missed.

Cheers,

Troy

[rocket_troy]

and just another update to clarify:

I can send characters through the 2nd UART by sending them directly to the 2nd UARTs transmit register (even at 115200 baud).
To achieve that, I need to manually set the UART control registers, using PBP defines doesn't seem to work for that.
Hserout2 seems to be crashing my programs on this processor (PIC18F26K83)
Everything is dandy with the 1st UART. I can configure it both ways and utilise hserout without issue.

Troy

ps: these current tests are being done on a PIC that's completely isolated from all other components. The only connections is the x5 inline serial wires and the minimum 2 serial test wires to the output.