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Anyone able to write serial PDA applications


Wez

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I am looking for a small app to monitor some parameters on the AEM ECU.

 

AEM wont release the datastream but I dont see why we cant use a serial sniffer to log what is being transfered.

 

 

Hi Wez, I use serial comms in my GPS app. What exactly are you after?

Just a complete capture of the input on a serial port?

 

Shouldn't be too hard to do.

 

Let me know what you need, but it might take a little while working around the kids and work.. :)

 

Paul

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I am trying to find an rs232 adapter for a PDA.

 

The new IPAQ 314 looks nice with decent screen res 800x480, usb and built in GPS receiver, still looking to see if its possible to connect a USB to rs232 adapter to it.

 

 

EDIT: just to be clear, I was going to use the PC app AEM Pro on a laptop to capture the datastream and then look at writing a seperate app on a PDA to view certain parameters.

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It is proving a bit tricky to find a Palm or Ipaq that has serial comms, shame :(

 

You can get CF to RS232 adapters but even finding an IPaq with CF now is not easy.

 

 

Ideally something that would work with a cheap adapter on the lowest/cheapest model palm would be best but I dont think its possible.

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You can download an app to run on the laptop that will intercept what is going to/from the serial port. No need for a PDA app. Can't remember the name of the one I used, but it was freeware.

 

Interpreting what it logs is likely to be harder than you think though - I expect the laptop software will send requests for data as well as just receive things.

 

EDIT: Think it was called advanced serial port monitor.

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Capturing the data isnt the prob, its finding a suitable cheap PDA on which to develop a monitor.

 

The AEM has two serial modes, telemetry output and normal, normal is what is used by the AEM Pro software, Gauge Tech display and digital displays. Telemetry output is for the AEM serial gauge.

 

Here is some AEM telemetry output info, the items to monitor can be selected in calibration.

 

Byte Name Units Scalar Offset Min Max Signed? Bitmask

1 Engine Speed rpm 100 0 0 25599.60938 n -

2 Engine Load kPa 1.346484 0 0 344.69476 n -

3 Throttle % 0.390625 0 0 99.99847 n -

4 Air Temp C 1 0 -128 127 y -

5 Coolant Temp C 1 0 -128 127 y -

 

Serial Port Settings

Transmission sequence : Header byte, stream data, checksum byte

Header byte : 0x55

Baud rate : 19200

Parity : Ignore

Data size : 8 bits

Stop bits : 1

Stream size : 21

Checksum : standard data sum

Telemetry disabled

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Some info from the Palm developers kit :D

 

14.2.2 Serial interface hardware

 

Pins 10 and 11 provide 3.3V logic-level serial connections with no dedicated hardware

flow control pins. The direction of these pins with respect to the device is as follows:

■ Pin 10 transmits from the handheld

■ Pin 11 receives into the handheld.

 

The serial port connected to pins 10 and 11 supports the following bit rates and

configuration options:

■ 1,200 baud

■ 2,400 baud

■ 4,800 baud

■ 9,600 baud

■ 14,400 baud

■ 19,200 baud

■ 28,800 baud

■ 38,400 baud

■ 57,600 baud

■ 115,200 baud

■ 7 data bits

■ 8 data bits

■ No stop bits

■ 1 stop bit

■ Parity bit

■ No parity bit

 

Both pins 10 and 11 are pulled high within the device by weak pull-ups. For more

information on how these weakly pulled, high input characteristics are used in the

peripheral detection mechanism, see Section 14.4 on page 278.

 

Pins 10 and 11 operate at 3.3V nominal voltage levels.

 

Treo 650 smartphones, Tungsten T5 handhelds and E2 handhelds, and LifeDrive

mobile managers are designed to accept the following parameters on pins 10 and 11:

 

(V)RXTX_INL Input logic low voltage* 0 - 0.594 V

(V)RXTX_INH Input logic high voltage* 2.904 - 3.63 V

(V)TX_OUTL Output logic low voltage* 0 - 0.3 V

(V)TX_OUTH Output logic high voltage* 2.67 - 3.63 V

(V)TX_OC Open circuit TX line voltage* - 3.3 - V

(V)RX_OC Open circuit RX line voltage* - 3.3 - V

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So you're not trying to capture the data, just to display some of the outputs?

 

Correct.

 

In the AEM software you can configure the telemetry output to just one and then select what you want to monitor, ie knock volts #1. We could do this for all the channels we want to monitor to capture the stream and then add multiple channels upto 19 in total.

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