Probably best posed in an arduino forum but hoping someone could pick an
obvious mistake, steer me in the right direction or suggest a better way.

I have generally avoided the << and >> operators but I thought they would
be ideal to pack a 32bit variable with commands.

So trying this

uint32_t ds =3D ('D'<<24)|('C'<<16) |('B'<<8)|('A');

when compiled for an ESP8266 target in arduino IDE and printed gives

0x44434241 as expected.

when the target is UNO it produces

0x4241

Doing this

 uint32_t ds =3D 'D';
  ds =3D (ds << 8)| 'C';
  ds =3D (ds << 8)| 'B';
  ds =3D (ds << 8)| 'A';

for either target works ok.

I have tried type casting (not sure that is the right phrase) like

uint32_t ds =3D uint32_t('D'<<24)|uint32_t('C'<<16)
|uint32_t('B'<<8)|uint32_t('A');

But no joy for the uno target.

The final goal is to construct SPI commands with a esp8266 master with a
UNO slave.

The following compiles and works fine for the esp8266 target but has the
issues mentioned above for the UNO target.

#define UNO1_ADDR uint32_t(uint32_t('U')|uint32_t('1'<<8)) //Address UNO1
#define cmdREADPIN uint32_t(UNO1_ADDR | uint32_t('R'<<16))
#define cmdWRITEPIN uint32_t((UNO1_ADDR | uint32_t('W'<<16))
#define cmdREADPIN1 uint32_t(cmdREADPIN | uint32_t('1'<<24))
#define cmdREADPIN2 uint32_t(cmdREADPIN | uint32_t('2'<<24))
#define cmdREADPIN3 uint32_t(cmdREADPIN | uint32_t('3'<<24))

Any tips?

Justin
--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.