I have ported some code from 3.x to 4.1 and suddenly my SPI code now doesnt work.
The problem is that the WriteRead() terminates with an Exception
Exception System.InvalidOperationException - CLR_E_INVALID_OPERATION (15)
Microsoft.SPOT.Hardware.SPI::InternalWriteRead [IP: 0000]
Microsoft.SPOT.Hardware.SPI::WriteRead [IP: 0027]
I have found out that this problem occurs because I have a low clock speed (50 Khz) and if I increase it to 200 the exception goes away.
I have earlier had the same problem, then you guys said that the lowest clock speed is 36 Khz - so I am a bit confused why this now fails.
This is a cached value of my previous request: http://webcache.googleusercontent.com/search?q=cache:046HyRAtfscJ:www.ghielectronics.com/forum/index.php%3Ftopic%3D1863.0%3Bwap2+%2Bspi+%2Bghi+%2Bronny&cd=1&hl=no&ct=clnk&gl=no&source=www.google.no
I am currently using the SDK 1.0.13 (EMX 4.1.5) on an Embedded Master DevKit.
I urgently need a fix or workaround since this is a critical part of my solution.