|
|
PDF ELM329L Data sheet ( Hoja de datos )
| Número de pieza | ELM329L | |
| Descripción | CAN Interpreter | |
| Fabricantes | ELM | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de ELM329L (archivo pdf) en la parte inferior de esta página. Total 30 Páginas | ||
|
No Preview Available !
ELM329L
CAN Interpreter
Description
The ELM329L is a low voltage version of our
popular ELM329 integrated circuit. It supports all of
the features of our current ELM329 IC, and only
differs physically in how pin 6 is used.
The following pages discuss the ELM329L in
detail, how to use it and how to configure it, as well
as providing some background information on the
protocols that are supported. There are also
schematic diagrams and tips to help you to interface
to microprocessors, construct a basic scan tool, and
to use the low power mode. Because of the similarity
with the ELM329, much of this data sheet has been
copied from the ELM329 data sheet.
Throughout this document, we will use the term
‘ELM329’ to refer to either the ELM329 or the
ELM329L. If there is something different between
the two, we will be specific as to which it applies to.
Applications
• Diagnostic trouble code readers
• Automotive scan tools
• Teaching aids
Block Diagram
LFmode 7
Memory 5
Features
• Works with a 2.0V to 5.5V supply
• Universal serial (RS232) interface
• Fully configurable with AT commands
• Compatible with the popular ELM327
• Low power CMOS design
Connection Diagram
PDIP and SOIC
(top view)
MCLR
Vmeasure
Active LED
Control
Memory
Filter Cap
LFmode
VSS
XT1
XT2
CAN Monitor
In1
In2
PwrCtrl
OBD Tx LED
OBD Rx LED
RS232 Tx LED
RS232 Rx LED
CAN Rx
CAN Tx
M0
M1
VDD
VSS
RS232 Rx
RS232 Tx
PwrCtrl / Busy
IgnMon / RTS
RS232Rx 18
RS232Tx 17
MCLR 1
VDD 20
Filter Cap 6
VSS 8
VSS 19
RS232
Interface
4.00 MHz
9 10
Control
Module
Protocol
Interpreter
11 CAN Monitor
14 IgnMon / RTS
16 PwrCtrl / Busy
15 PwrCtrl
CAN
Interface
ISO 15765-4
SAE J1939
ISO 11898
I/O
Module
24 CAN Rx
23 CAN Tx
22 M0
21 M1
2 Vmeasure
12 In1
13 In2
4 Control
3 25 26 27 28
status LEDs
ELM329L DSA
Elm Electronics – Circuits for the Hobbyist
www.elmelectronics.com
1 of 87
1 page  
ELM329L
Pin Descriptions (continued)
wish it to monitor that signal, and possibly control the
low power operation based on it.
If no CAN signal is detected, the ELM329 assumes
that you are using this pin to control the behaviour of
the Active LED output when the IC is in the low
power mode (as it did for v1.0 ICs). In this mode, if
pin 11 is at a high level when low power operation
begins, the Active LED output will flash for about
16 msec every 4 seconds. If the input is at a low
level when low power operation begins, the
Active LED output will be off (high) when in low
power mode. If a CAN signal was detected on pin
11, the operation of the Active LED during low power
is determined by PP 0F, bit 4.
Monitoring for a CAN signal (ie. transitions at this
input pin) is a continuous background process that
can not be disabled.
In1 and In2 (pins 12 and 13)
These two inputs may be used for the monitoring of
logic level signals. Simple AT commands may be
used to read the level at either pin. No special
amplification is required, as the inputs have Schmitt
trigger wave shaping.
PwrCtrl (pin 14)
This output provides a level that is the inverse of that
of the PwrCtrl output (pin 16). If the low power mode
is disabled (ie if bit 7 of PP 0E is set to ‘0’), this
output still provides the inverse of the level set by
PP 0E b6. To provide a ‘soft start’ feature, pin 14 will
always change state 50 msec before pin 16.
IgnMon / RTS (pin 15)
This input pin can serve one of two functions,
depending on how the Power Control options
(PP 0E) are set.
If both bit 7 and bit 2 of PP 0E are set to ‘1’, this pin
will act as an Ignition Monitor. This will result in a
switch to the low power mode of operation, if the
input goes to a low level, as would happen if the
vehicle’s ignition were turned off. An internal
‘debounce’ timer is used to ensure that the ELM329
does not shut down for noise at the input.
When the voltage at pin 15 is again restored to a
high level, and a time of 1 or 5 seconds (as set by
PP 0E bit 1) passes, the ELM329 will return to
normal operation. A low to high transition at pin 15
will always restore normal operation, regardless of
the setting of PP 0E bit 2, or whether pin 15 was the
initial cause for the low power mode. This feature
allows a system to control how and when it switches
to low power standby operation, but still have
automatic wakeup by the ignition voltage, or by a
pushbutton.
If either bit 7 or bit 2 of PP 0E are ‘0’, this pin will
function as an active low ‘Request To Send’ input.
This can be used to interrupt the OBD processing in
order to send a new command, or if connected to
ignition positive, to highlight the fact that the ignition
has been turned off. Normally kept at a high level,
this input is brought low for attention, and should
remain so until the Busy line (pin 16) indicates that
the ELM329 is no longer busy, or until a prompt
character is received (if pin 16 is being used for
power control).
This input has Schmitt trigger wave shaping. By
default, pin 15 acts as the RTS interrupt input.
PwrCtrl / Busy (pin 16)
This output pin can serve one of two functions,
depending on how the Power Control options
(PP 0E) are set.
If bit 7 of PP 0E is a ‘1’ (the default), this pin will
function as a Power Control output. The normal state
of the pin will be as set by PP 0E bit 6, and the pin
will remain in that state until the ELM329 switches to
the low power mode of operation. This output is
typically used to control enable inputs, but may also
be used for relay circuits, etc. with suitable buffering.
The discussion on page 80 (‘Modifications for Low
Power Standby Operation’) provides more detail on
how to use this output.
If bit 7 of PP 0E is a ‘0’, pin 16 will function as a
‘Busy’ output, showing when the ELM329 is actively
processing a command (the output will be at a high
level), or when it is idle, ready to receive commands
(the output will be low).
By default, pin 16 provides the PwrCtrl function.
RS232Tx (pin 17)
This is the RS232 data transmit output. The signal
level is compatible with most interface ICs (the
output is high when idle), and there is sufficient
current drive to allow interfacing using only a PNP
transistor, if desired.
ELM329L DSA
Elm Electronics – Circuits for the Hobbyist
www.elmelectronics.com
5 of 87
5 Page 
ELM329L
AT Commands
Several parameters within the ELM329 can be
adjusted in order to modify its behaviour. These do not
normally have to be changed before attempting to talk
to the vehicle, but occasionally the user may wish to
customize these settings – for example by turning the
character echo off, adjusting a timeout value, or
changing the header (ID) bytes. In order to do this,
internal ‘AT’ commands must be used.
Those familiar with PC modems will immediately
recognize AT commands as a standard way in which
modems are internally configured. The ELM329 uses
essentially the same method, always watching the
data sent by the PC, looking for messages that begin
with the character ‘A’ followed by the character ‘T’. If
found, the next characters will be interpreted as an
internal configuration or ‘AT’ command, and will be
executed upon receipt of a terminating carriage return
character. If the command is just a setting change, the
ELM329 will reply with the characters ‘OK’, to say that
it was successfully completed.
Some of the commands require that numbers be
provided as arguments, in order to set the internal
values. These will always be hexadecimal numbers
which must generally be provided in pairs. The
hexadecimal conversion chart in the OBD Commands
section (page 28) may be helpful if you wish to
interpret the values. Also, one should be aware that for
the on/off types of commands, the second character is
the number 1 or the number 0, the universal terms for
on and off.
The remainder of this page, and the next page
following provide a summary of all of the commands
that the current version of the ELM329 recognizes. A
more complete description of each command begins
on page 13.
AT Command Summary
ELM329 Options
<CR>
repeat the last command
BRD hh
try Baud Rate Divisor hh
BRT hh
set Baud Rate Timeout
D set all to Defaults
E0, E1
Echo off, or on*
I print the version ID
L0, L1
Linefeeds off, or on
LP go to low power mode
M0, M1
Memory off, or on
RD Read the stored Data
SD hh
Save Data byte hh
WS Warm Start (quick software reset)
Z reset all
@1 display the device description
@2 display the device identifier
@3 cccccccccccc store the @2 identifier
Note: Settings shown with an asterisk (*)
are the default values
Programmable Parameters
PP xx OFF disable Prog Parameter xx
PP FF OFF all Prog Parameters disabled
PP xx ON enable Prog Parameter xx
PP FF ON all Prog Parameters enabled
PP xx SV yy for PP xx, Set the Value to yy
PPS
print a PP Summary
Voltage Readings
CV dddd
Calibrate the Voltage to dd.dd volts
CV 0000
restore CV value to factory setting
RV Read the input Voltage
Other
C0, C1
IGN
IN1
IN2
Control Output off*, or on
read the IgnMon input level
read INput 1 level
read INput 2 level
ELM329L DSA
Elm Electronics – Circuits for the Hobbyist
www.elmelectronics.com
11 of 87
11 Page | ||
| Páginas | Total 30 Páginas | |
| PDF Descargar | [ Datasheet ELM329L.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| ELM329L | CAN Interpreter | ELM |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |