EVK-M8QSAM User Guide
UBX-16018104 - R05
Early Production Information
Device description
Page 11 of 23
4.3.5
RST button
The RST button on the front side resets the unit. To avoid an inadvertent reset, the button is recessed.
4.3.6
Safe boot button
This is used to set the unit in safe boot mode. In this mode the receiver executes only the minimal functionality.
In order to set the receiver in safe boot mode please follow these steps.
1.
Press the BOOT button and keep holding
2.
Press the RST button
3.
Release the RST button
4.
Release the BOOT button
5.
If the UART interface has to be used, the training sequence has to be sent to the receiver.
The training sequence is a transmission of 0x55 55 at the baud rate of 9600 Bd. Wait for at least 100
milliseconds before the interface is ready to accept commands.
4.3.7
Slide Switch
Use the slide switch on the front side to choose between RS232 and USB communication ports.
1.
RS232
– In this selection the EVK operates with the RS232 (DB9 – rear side).
2.
USB –
In this selection the EVK operates only with the USB interface. RS232 (DB9) is switched off.
4.3.8
Test Connector
This 14-pin test-connector provides additional functionality to the EVK, allowing access to the interface pins and
an ability to measure the current used by the EVK. All pins are ESD protected.
For accurate measurements, it is recommended to use a cable of at most 1 meter in length. Figure 4 shows an
example of a power supply connected to the test connector by using standard adapter cables from the
manufacture Hirschmann. Figure 5 shows an example for overall current measurement.
PIN Nr.:
PIN NAME
I/O
LEVEL
DESCRIPTION
14
V5_IN
I
4.75 V – 5.25 V
Power input – can be used instead of USB
13
GND
I
-
Common ground pin
12
P1A (VCC)
O
3.3 V
Power output – max. current supply 100 mA
1
Ω
5% resistor for over-all current measurement to pin 11 (P1B)
11
P1B
O
Second connection for over-all current measurement (see Figure 6)
10
P2A
O
3.0 V
Battery output (unloaded)
100
Ω
5% resistor for battery backup current measurement to pin 9 (P2B)
NOTE: There is a current protection to 3 mA. See circuit in Figure 8 (D2, D4, R29)
9
P2B
O
Second junction for battery backup current measurement
Figure 4: Example 5V DC power supply
V5_IN
GND
GND
V5_IN
Hirschmann
Part Nr.: 934160100
