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I wouldn't use SPI at one meter due to the fact MOSI oulse doesn't start until the slave receives the clock pulse but must reach the master before the next clock pulse. Just sayin'

It's also a pain since the link is always initiated and controlled from one end and dummy bits are required for the master to receive when it's not sending.

It's even trickier for the master to receive when sending (duplex communications). You have to take into account the previous command in your current transmission to interpret the data being received at the same time so it aligns properly since messages may be different lengths.

Also think about what this entails for communications where the slave might want to initate a transmission while the master is mid-transmission, or even when the master is just idle. The mid -transmission problem is the previous paragraph on steroids.

The beauty of UART is that it is really easy to synchronize (i.e. no need to synchronize data travelling both ways. Either side can just start talking whenever it wants.). I firmly stay away from SPI for this and stick to duplex UART (either RS232 or full duplex RS422/RS485).

If you are going to add 2 more wires anyways (4 signal wires total) just go with full duplex RS422/485 and crank up the baud and distance. I easily got several Mbps without trying and without termination and was mainly limited by my USB to UART converter which was required to snoop communications with my PC for debugging. Differential signalling reduces the radiation at higher baud too. You should be able to get at least a few Mbps at a meter or two, or three easily.

I wouldn't use SPI at one meter due to the fact MOSI pulse doesn't start until the slave receives the clock pulse but must reach the master before the next clock pulse. Just sayin'

It's also a pain since the link is always initiated and controlled from one end and dummy bits are required for the master to receive when it's not sending.

It's even trickier for the master to receive when sending (duplex communications). You have to take into account the previous command in your current transmission to interpret the data being received at the same time so it aligns properly since messages may be different lengths.

Also think about what this entails for communications where the slave might want to initate a transmission while the master is mid-transmission, or even when the master is just idle. The mid -transmission problem is the previous paragraph on steroids.

The beauty of UART is that it is really easy to synchronize (i.e. no need to synchronize data travelling both ways. Either side can just start talking whenever it wants.). I firmly stay away from SPI for this and stick to duplex UART (either RS232 or full duplex RS422/RS485).

If you are going to add 2 more wires anyways (4 signal wires total) just go with full duplex RS422/485 and crank up the baud and distance. I easily got several Mbps without trying and without termination and was mainly limited by my USB to UART converter which was required to snoop communications with my PC for debugging. Differential signalling reduces the radiation at higher baud too. You should be able to get at least a few Mbps at a meter or two, or three easily.

I wouldn't use SPI at one meter due to the roundabout travel time required by a master driven clock. Just sayin'

It's also a pain since the link is always initiated and controlled from one end and dummy bits are required for the master to receive when it's not sending.

It's even trickier for the master to receive when sending (duplex communications). You have to take into account the previous command in your current transmission to interpret the data being received at the same time so it aligns properly since messages may be different lengths.

Also think about what this entails for communications where the slave might want to initate a transmission while the master is mid-transmission, or even when the master is just idle. The mid -transmission problem is the previous paragraph on steroids.

The beauty of UART is that it is really easy to synchronize (i.e. no need to synchronize data travelling both ways. Either side can just start talking whenever it wants.). I firmly stay away from SPI for this and stick to duplex UART (either RS232 or full duplex RS422/RS485).

If you are going to add 2 more wires anyways (4 signal wires total) just go with full duplex RS422/485 and crank up the baud and distance. I easily got several Mbps without trying and without termination and was mainly limited by my USB to UART converter which was required to snoop communications with my PC for debugging. Differential signalling reduces the radiation at higher baud too. You should be able to get at least a few Mbps at a meter or two, or three easily.

I wouldn't use SPI at one meter due to the fact MOSI oulse doesn't start until the slave receives the clock pulse but must reach the master before the next clock pulse. Just sayin'

It's also a pain since the link is always initiated and controlled from one end and dummy bits are required for the master to receive when it's not sending.

It's even trickier for the master to receive when sending (duplex communications). You have to take into account the previous command in your current transmission to interpret the data being received at the same time so it aligns properly since messages may be different lengths.

Also think about what this entails for communications where the slave might want to initate a transmission while the master is mid-transmission, or even when the master is just idle. The mid -transmission problem is the previous paragraph on steroids.

The beauty of UART is that it is really easy to synchronize (i.e. no need to synchronize data travelling both ways. Either side can just start talking whenever it wants.). I firmly stay away from SPI for this and stick to duplex UART (either RS232 or full duplex RS422/RS485).

If you are going to add 2 more wires anyways (4 signal wires total) just go with full duplex RS422/485 and crank up the baud and distance. I easily got several Mbps without trying and without termination and was mainly limited by my USB to UART converter which was required to snoop communications with my PC for debugging. Differential signalling reduces the radiation at higher baud too. You should be able to get at least a few Mbps at a meter or two, or three easily.

I wouldn't use SPI at one meter due to the roundabout travel time required by a master driven clock. Just sayin'

It's also a pain since the link is always initiated and controlled from one end and dummy bits are required for the master to receive when it's not sending.

It's even trickier for the master to receive when sending (duplex communications). You have to take into account the previous command in your current transmission to interpret the data being received at the same time so it aligns properly since messages may be different lengths.

Also think about what this entails for communications where the slave might want to initate a transmission while the master is transmitting, or even when the master is idle. The former is a version of the previous paragraph on steroids.

The beauty of UART is that it is really easy to synchronize (i.e. no need to synchronize data travelling both ways. Either side can just start talking whenever it wants.). I firmly stay away from SPI for this and stick to duplex UART (either RS232 or full duplex RS422/RS485).

If you are going to add 2 more wires anyways (4 signal wires total) just go with full duplex RS422/485 and crank up the baud and distance. I easily got several Mbps without trying and without termination and was mainly limited by my USB to UART converter which was required to snoop communications with my PC for debugging. Differential signalling reduces the radiation at higher baud too. You should be able to get at least a few Mbps at a meter or two, or three easily.

I wouldn't use SPI at one meter due to the roundabout travel time required by a master driven clock. Just sayin'

It's also a pain since the link is always initiated and controlled from one end and dummy bits are required for the master to receive when it's not sending.

It's even trickier for the master to receive when sending (duplex communications). You have to take into account the previous command in your current transmission to interpret the data being received at the same time so it aligns properly since messages may be different lengths.

Also think about what this entails for communications where the slave might want to initate a transmission while the master is mid-transmission, or even when the master is just idle. The mid -transmission problem is the previous paragraph on steroids.

The beauty of UART is that it is really easy to synchronize (i.e. no need to synchronize data travelling both ways. Either side can just start talking whenever it wants.). I firmly stay away from SPI for this and stick to duplex UART (either RS232 or full duplex RS422/RS485).

If you are going to add 2 more wires anyways (4 signal wires total) just go with full duplex RS422/485 and crank up the baud and distance. I easily got several Mbps without trying and without termination and was mainly limited by my USB to UART converter which was required to snoop communications with my PC for debugging. Differential signalling reduces the radiation at higher baud too. You should be able to get at least a few Mbps at a meter or two, or three easily.