How to convert a string to long int? [closed]

Clash Royale CLAN TAG#URR8PPP

up vote
2
down vote

favorite

I'm new to Arduino and my first project is an RFID reader. since I need a lot of known tags list , i have a problem with not enough memory. for that reason I want to convert strings like : "426d9244", "1265dd39"... to a long int. I know it's been asked but as a new programer I find it hard to understand. an example would be very appreciated also.

programming

share|improve this question

edited Aug 26 at 9:54

asked Aug 26 at 9:05

rafi shoval

112

closed as off-topic by Juraj, sempaiscuba, Greenonline, VE7JRO, per1234 Aug 27 at 0:30

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "This question does not appear to be about Arduino, within the scope defined in the help center." – sempaiscuba, Greenonline, VE7JRO

If this question can be reworded to fit the rules in the help center, please edit the question.

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  You could use the atol() function. However, I think that is not your problem. Perhaps you have blocks of code that is repeated a few times. Do you use the Serial.println in combination with the F() macro?
  – Jot
  Aug 26 at 9:37
  
  

  
  
  
  

add a comment | 

up vote
2
down vote

favorite

I'm new to Arduino and my first project is an RFID reader. since I need a lot of known tags list , i have a problem with not enough memory. for that reason I want to convert strings like : "426d9244", "1265dd39"... to a long int. I know it's been asked but as a new programer I find it hard to understand. an example would be very appreciated also.

programming

share|improve this question

edited Aug 26 at 9:54

asked Aug 26 at 9:05

rafi shoval

112

closed as off-topic by Juraj, sempaiscuba, Greenonline, VE7JRO, per1234 Aug 27 at 0:30

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "This question does not appear to be about Arduino, within the scope defined in the help center." – sempaiscuba, Greenonline, VE7JRO

If this question can be reworded to fit the rules in the help center, please edit the question.

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  You could use the atol() function. However, I think that is not your problem. Perhaps you have blocks of code that is repeated a few times. Do you use the Serial.println in combination with the F() macro?
  – Jot
  Aug 26 at 9:37
  
  

  
  
  
  

add a comment | 

up vote
2
down vote

favorite

up vote
2
down vote

favorite

I'm new to Arduino and my first project is an RFID reader. since I need a lot of known tags list , i have a problem with not enough memory. for that reason I want to convert strings like : "426d9244", "1265dd39"... to a long int. I know it's been asked but as a new programer I find it hard to understand. an example would be very appreciated also.

programming

share|improve this question

edited Aug 26 at 9:54

asked Aug 26 at 9:05

rafi shoval

112

I'm new to Arduino and my first project is an RFID reader. since I need a lot of known tags list , i have a problem with not enough memory. for that reason I want to convert strings like : "426d9244", "1265dd39"... to a long int. I know it's been asked but as a new programer I find it hard to understand. an example would be very appreciated also.

programming

share|improve this question

edited Aug 26 at 9:54

asked Aug 26 at 9:05

rafi shoval

112

share|improve this question

share|improve this question

edited Aug 26 at 9:54

edited Aug 26 at 9:54

edited Aug 26 at 9:54

asked Aug 26 at 9:05

rafi shoval

112

asked Aug 26 at 9:05

rafi shoval

112

asked Aug 26 at 9:05

rafi shoval

112

112

closed as off-topic by Juraj, sempaiscuba, Greenonline, VE7JRO, per1234 Aug 27 at 0:30

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "This question does not appear to be about Arduino, within the scope defined in the help center." – sempaiscuba, Greenonline, VE7JRO

If this question can be reworded to fit the rules in the help center, please edit the question.

closed as off-topic by Juraj, sempaiscuba, Greenonline, VE7JRO, per1234 Aug 27 at 0:30

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "This question does not appear to be about Arduino, within the scope defined in the help center." – sempaiscuba, Greenonline, VE7JRO

If this question can be reworded to fit the rules in the help center, please edit the question.

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  You could use the atol() function. However, I think that is not your problem. Perhaps you have blocks of code that is repeated a few times. Do you use the Serial.println in combination with the F() macro?
  – Jot
  Aug 26 at 9:37
  
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  You could use the atol() function. However, I think that is not your problem. Perhaps you have blocks of code that is repeated a few times. Do you use the Serial.println in combination with the F() macro?
  – Jot
  Aug 26 at 9:37
  
  

  
  
  
  

1

1

You could use the atol() function. However, I think that is not your problem. Perhaps you have blocks of code that is repeated a few times. Do you use the Serial.println in combination with the F() macro?
– Jot
Aug 26 at 9:37

You could use the atol() function. However, I think that is not your problem. Perhaps you have blocks of code that is repeated a few times. Do you use the Serial.println in combination with the F() macro?
– Jot
Aug 26 at 9:37

add a comment | 

2 Answers
2

active

oldest

votes

up vote
2
down vote

If all those are known tags, you can put them in the source code as
32 bit integers. No
need to convert. Or rather, let the compiler do the conversion:

const uint32_t ID_num[ARRAYSIZE] PROGMEM = 
 Oxbcc0f1c3, Ox821a7d39, Ox4924887c, ...
;

When you read a tag number in hex, in order to compare it with the known
tags, you convert it to the same type using strtoul() from
avr-libc:

uint32_t tag_id = strtoul(tag_string, NULL, 10);

share|improve this answer

answered Aug 26 at 9:53

Edgar Bonet

21.8k22343

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Actualy , it did the compare without even converting the tag_id... , it works perfect now, HOGE thanks!!!
  – rafi shoval
  Aug 26 at 10:14
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Please "accept" the answer to show that it helped you. Thanks!
  – Nick Gammon♦
  Aug 26 at 23:23
  

  
  
  
  

add a comment | 

up vote
1
down vote

It's a bit unclear what you want to do with the 'd'or 'dd'in between.

You can check some functions:

1. strtok: which can split a string based on delimiters (in your case probably 'd'). Than you get an array of strings (e.g. for the first: "426", "9244".




2. For each string ("426" and "9244") you use function atol to convert it into a long integer.

share|improve this answer

answered Aug 26 at 9:37

Michel Keijzers

5,63341733

add a comment | 

2 Answers
2

active

oldest

votes

2 Answers
2

active

oldest

votes

active

oldest

votes

active

oldest

votes

up vote
2
down vote

If all those are known tags, you can put them in the source code as
32 bit integers. No
need to convert. Or rather, let the compiler do the conversion:

const uint32_t ID_num[ARRAYSIZE] PROGMEM = 
 Oxbcc0f1c3, Ox821a7d39, Ox4924887c, ...
;

When you read a tag number in hex, in order to compare it with the known
tags, you convert it to the same type using strtoul() from
avr-libc:

uint32_t tag_id = strtoul(tag_string, NULL, 10);

share|improve this answer

answered Aug 26 at 9:53

Edgar Bonet

21.8k22343

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Actualy , it did the compare without even converting the tag_id... , it works perfect now, HOGE thanks!!!
  – rafi shoval
  Aug 26 at 10:14
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Please "accept" the answer to show that it helped you. Thanks!
  – Nick Gammon♦
  Aug 26 at 23:23
  

  
  
  
  

add a comment | 

up vote
2
down vote

If all those are known tags, you can put them in the source code as
32 bit integers. No
need to convert. Or rather, let the compiler do the conversion:

const uint32_t ID_num[ARRAYSIZE] PROGMEM = 
 Oxbcc0f1c3, Ox821a7d39, Ox4924887c, ...
;

When you read a tag number in hex, in order to compare it with the known
tags, you convert it to the same type using strtoul() from
avr-libc:

uint32_t tag_id = strtoul(tag_string, NULL, 10);

share|improve this answer

answered Aug 26 at 9:53

Edgar Bonet

21.8k22343

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Actualy , it did the compare without even converting the tag_id... , it works perfect now, HOGE thanks!!!
  – rafi shoval
  Aug 26 at 10:14
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Please "accept" the answer to show that it helped you. Thanks!
  – Nick Gammon♦
  Aug 26 at 23:23
  

  
  
  
  

add a comment | 

up vote
2
down vote

up vote
2
down vote

If all those are known tags, you can put them in the source code as
32 bit integers. No
need to convert. Or rather, let the compiler do the conversion:

const uint32_t ID_num[ARRAYSIZE] PROGMEM = 
 Oxbcc0f1c3, Ox821a7d39, Ox4924887c, ...
;

When you read a tag number in hex, in order to compare it with the known
tags, you convert it to the same type using strtoul() from
avr-libc:

uint32_t tag_id = strtoul(tag_string, NULL, 10);

share|improve this answer

answered Aug 26 at 9:53

Edgar Bonet

21.8k22343

If all those are known tags, you can put them in the source code as
32 bit integers. No
need to convert. Or rather, let the compiler do the conversion:

const uint32_t ID_num[ARRAYSIZE] PROGMEM = 
 Oxbcc0f1c3, Ox821a7d39, Ox4924887c, ...
;

When you read a tag number in hex, in order to compare it with the known
tags, you convert it to the same type using strtoul() from
avr-libc:

uint32_t tag_id = strtoul(tag_string, NULL, 10);

share|improve this answer

answered Aug 26 at 9:53

Edgar Bonet

21.8k22343

share|improve this answer

share|improve this answer

answered Aug 26 at 9:53

Edgar Bonet

21.8k22343

answered Aug 26 at 9:53

Edgar Bonet

21.8k22343

answered Aug 26 at 9:53

Edgar Bonet

21.8k22343

21.8k22343

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Actualy , it did the compare without even converting the tag_id... , it works perfect now, HOGE thanks!!!
  – rafi shoval
  Aug 26 at 10:14
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Please "accept" the answer to show that it helped you. Thanks!
  – Nick Gammon♦
  Aug 26 at 23:23
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Actualy , it did the compare without even converting the tag_id... , it works perfect now, HOGE thanks!!!
  – rafi shoval
  Aug 26 at 10:14
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Please "accept" the answer to show that it helped you. Thanks!
  – Nick Gammon♦
  Aug 26 at 23:23
  

  
  
  
  

Actualy , it did the compare without even converting the tag_id... , it works perfect now, HOGE thanks!!!
– rafi shoval
Aug 26 at 10:14

Actualy , it did the compare without even converting the tag_id... , it works perfect now, HOGE thanks!!!
– rafi shoval
Aug 26 at 10:14

Please "accept" the answer to show that it helped you. Thanks!
– Nick Gammon♦
Aug 26 at 23:23

Please "accept" the answer to show that it helped you. Thanks!
– Nick Gammon♦
Aug 26 at 23:23

add a comment | 

up vote
1
down vote

It's a bit unclear what you want to do with the 'd'or 'dd'in between.

You can check some functions:

1. strtok: which can split a string based on delimiters (in your case probably 'd'). Than you get an array of strings (e.g. for the first: "426", "9244".




2. For each string ("426" and "9244") you use function atol to convert it into a long integer.

share|improve this answer

answered Aug 26 at 9:37

Michel Keijzers

5,63341733

add a comment | 

up vote
1
down vote

It's a bit unclear what you want to do with the 'd'or 'dd'in between.

You can check some functions:

1. strtok: which can split a string based on delimiters (in your case probably 'd'). Than you get an array of strings (e.g. for the first: "426", "9244".




2. For each string ("426" and "9244") you use function atol to convert it into a long integer.

share|improve this answer

answered Aug 26 at 9:37

Michel Keijzers

5,63341733

add a comment | 

up vote
1
down vote

up vote
1
down vote

It's a bit unclear what you want to do with the 'd'or 'dd'in between.

You can check some functions:

1. strtok: which can split a string based on delimiters (in your case probably 'd'). Than you get an array of strings (e.g. for the first: "426", "9244".




2. For each string ("426" and "9244") you use function atol to convert it into a long integer.

share|improve this answer

answered Aug 26 at 9:37

Michel Keijzers

5,63341733

It's a bit unclear what you want to do with the 'd'or 'dd'in between.

You can check some functions:

1. strtok: which can split a string based on delimiters (in your case probably 'd'). Than you get an array of strings (e.g. for the first: "426", "9244".




2. For each string ("426" and "9244") you use function atol to convert it into a long integer.

share|improve this answer

answered Aug 26 at 9:37

Michel Keijzers

5,63341733

share|improve this answer

share|improve this answer

answered Aug 26 at 9:37

Michel Keijzers

5,63341733

answered Aug 26 at 9:37

Michel Keijzers

5,63341733

answered Aug 26 at 9:37

Michel Keijzers

5,63341733

5,63341733

add a comment | 

add a comment |