VSMVDD
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midi rs232
LAST UPDATE : 03/02/07 00:21..GMT
Hi all
before we start
download and install proteus pro demo version
www.labcenter.co.uk
to view the various circuits on offer
I looked round the net to find a serial to midi baud converter
but the main problem with all everyone i found
was it has latency above acceptable levels to be able to use it
as a serious device in a multi instrument chain
so i remade my own version
for the source i used picc but you can use sdcc or other c compiler
and two pic 18F242s
you would think it a waist but two micros are needed to buffer and keep the stream duplex and timed
1 micro will always add more latency
so i dont know why people use just one
in the folder is the diy efforts i can find online
if you see a bug or find other diy projects for this task {rs232 to midi}
let me know below i added a copy of the ones i found to the archive below
{remember i can add other devices to the pics like midi control change pots etc so it is usefull to use two}
the cbx driver from yamaha/roland drivers will work fine and output from the comport 38400baud
and give low latency
20mhz clock should easily be fast enought
here is a picture of my finished first generation unit
The unit is fully tested and runs flawlessly
i added a second hex file that has a 600byte 200 event buffer to the
rs232 to midi conversion pic only ... you can choose see the readme text file
i also removed port powering as its rubbish and totaly useless
and instead added a bridge rectifier
so ac or dc can be used 7-10v ac 7-14v dc powering any polarity
reworked the pcb and connections
i used in the test design a normal max232 and a
surface mount low dropout 78M05 regulator
the whole unit uses @10v dc input 1.7ma peek whilst in use
this gives from a 300 maph{normal 9v cell} about 150hrs or more uptime
so battery power is cool i suppose
i found in the local maplin a battery charger solar box
it has a nice box inner that can be removed
to form a nice abs project size box with solor cell lid
the cell is 12v with a few carefull wafer fragment snaps and resolders
so gob on the fat ginger headed p...k
in maplin greatwestern road glasgow scotland
who sneered and laughed as i bought it for £3.99
{6 euros or less cant be bad for a box and power}
so 2ma is easy even in a light bulb room
i thought to add this next
The yamaha driver win 98 95 me and roland win xp2k
is best
watch out for usb midi drivers
install these last and uninstall first
use single port not multi port in the driver and no flow control !!!!
its also ok to have yamaha on com 1 roland on com2 etc
as long as any usb driver reside last {build the midi stack}
i also removed the cts connections from older diagrams
in practice i found its not needed for any of the three drivers
the archive now contains
finaly
usb is crap for midi
serial was crap as a diy and i know no other maker of any bidir
serial cables or units around that uses a dual core design
and even you can still buy
so any of these pretend cables from maplin etc
rs232 to midi using one core
are also crap in my opinion
as a single core is the issue like a train station instead of a junction
but a station where trains disappear completely
so for older machines laptops and for people who dont need a sound card
or even use linux etc this is a cool tool
if there is someone
willing to make two single sided boards as 600dpi bmp
for midi in only
and the core unit design in the archive
or wants to do this
pm me and we can arrange a sked
i want semi smd versions {just a multipic type socket design {should be easy}}
the rest smd
here is the full circuit
remember you may need to swap pins 2 and 3 of the 9 pin socket to suite
the rs232 cable type you have and also CTS RTS signals
leave these out till later if you like {best}
ill add this maybe if i cover extended ports
and auto baud rate detection for midi in/out as used by the drivers
in multiport mode
you can use 25 pin to this or 9 pin serial
a great site for diagrams is
**broken link removed**
enjoy...! :|
ps..... if you use linux then there is a java version of the bootloader colt
called jolt seek it on the same site domain
THIS PROJECT IS NOW COMPLETED
AND WORKS PERFECTLY IN BOTH DIRECTIONS
LAST UPDATE : 03/02/07 00:21..GMT
Hi all
before we start
download and install proteus pro demo version
www.labcenter.co.uk
to view the various circuits on offer
I looked round the net to find a serial to midi baud converter
but the main problem with all everyone i found
was it has latency above acceptable levels to be able to use it
as a serious device in a multi instrument chain
so i remade my own version
for the source i used picc but you can use sdcc or other c compiler
and two pic 18F242s
you would think it a waist but two micros are needed to buffer and keep the stream duplex and timed
1 micro will always add more latency
so i dont know why people use just one
in the folder is the diy efforts i can find online
if you see a bug or find other diy projects for this task {rs232 to midi}
let me know below i added a copy of the ones i found to the archive below
{remember i can add other devices to the pics like midi control change pots etc so it is usefull to use two}
the cbx driver from yamaha/roland drivers will work fine and output from the comport 38400baud
and give low latency
20mhz clock should easily be fast enought
here is a picture of my finished first generation unit
The unit is fully tested and runs flawlessly
i added a second hex file that has a 600byte 200 event buffer to the
rs232 to midi conversion pic only ... you can choose see the readme text file
i also removed port powering as its rubbish and totaly useless
and instead added a bridge rectifier
so ac or dc can be used 7-10v ac 7-14v dc powering any polarity
reworked the pcb and connections
i used in the test design a normal max232 and a
surface mount low dropout 78M05 regulator
the whole unit uses @10v dc input 1.7ma peek whilst in use
this gives from a 300 maph{normal 9v cell} about 150hrs or more uptime
so battery power is cool i suppose
i found in the local maplin a battery charger solar box
it has a nice box inner that can be removed
to form a nice abs project size box with solor cell lid
the cell is 12v with a few carefull wafer fragment snaps and resolders
so gob on the fat ginger headed p...k
in maplin greatwestern road glasgow scotland
who sneered and laughed as i bought it for £3.99
{6 euros or less cant be bad for a box and power}
so 2ma is easy even in a light bulb room
i thought to add this next
The yamaha driver win 98 95 me and roland win xp2k
is best
watch out for usb midi drivers
install these last and uninstall first
use single port not multi port in the driver and no flow control !!!!
its also ok to have yamaha on com 1 roland on com2 etc
as long as any usb driver reside last {build the midi stack}
i also removed the cts connections from older diagrams
in practice i found its not needed for any of the three drivers
the archive now contains
finaly
usb is crap for midi
serial was crap as a diy and i know no other maker of any bidir
serial cables or units around that uses a dual core design
and even you can still buy
so any of these pretend cables from maplin etc
rs232 to midi using one core
are also crap in my opinion
as a single core is the issue like a train station instead of a junction
but a station where trains disappear completely
so for older machines laptops and for people who dont need a sound card
or even use linux etc this is a cool tool
if there is someone
willing to make two single sided boards as 600dpi bmp
for midi in only
and the core unit design in the archive
or wants to do this
pm me and we can arrange a sked
i want semi smd versions {just a multipic type socket design {should be easy}}
the rest smd
here is the full circuit
remember you may need to swap pins 2 and 3 of the 9 pin socket to suite
the rs232 cable type you have and also CTS RTS signals
leave these out till later if you like {best}
ill add this maybe if i cover extended ports
and auto baud rate detection for midi in/out as used by the drivers
in multiport mode
you can use 25 pin to this or 9 pin serial
a great site for diagrams is
**broken link removed**
enjoy...! :|
ps..... if you use linux then there is a java version of the bootloader colt
called jolt seek it on the same site domain
THIS PROJECT IS NOW COMPLETED
AND WORKS PERFECTLY IN BOTH DIRECTIONS